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Electro-Voice 1252 Computer Monitor User Manual

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1. Efectrofdustries Gauge Tech T NE Us A Power Su pply Max Power 124 Input Voltage 1260 DC D sozawwacioc O Output Voltage 12V DC Figure 9 4 Power flow from PSIO to I O Module Figure 9 5 Labels for the PSIO Power Source Labels are Red amp White G Electro Industries GaugeTech Doc E107706 V1 25 9 4 9 3 Using PSIO with Multiple UO Modules LEDs Communication ONLY Female A B and RS 485 a Shield Side Port INPUT 1 INPUT 1 A Power INPUT 2 INPUT 2 INPUT 3 INPUT 3 P ower Suppl INPUT 4 INPUT 4 PSIO PP y INPUT 5 INPUT 5 Max Power 12 VA INPUT 6 INPUT 6 Input Voltage 12 60 DC O INPUT 7 INPUT 7 90 240v AC DC O INPUT 8 INPUTS Output Voltage 12 DC ElectroindustriesiGaugeTech wwww electroind com Reset Button Mounting Bracket 1 O Port Size and pin configuration vary Figure 9 6 Using PSIO with Multiple I O Modules NOTE PSIO must be to the right of UO Modules when viewing the side label as shown 9 3 1 Steps for Attaching Multiple 1 0 Modules 1 Each I O module in a group must be assigned a unique address See the Communicator EXT User Manual for details on configuring and programming the O Modules 2 Determine how many power sources such as PSIO are needed for the number of modules in use See section 9 2 1 for details 3 Starting with the left module and using a slotted screw driver fasten the first I O Module to the left
2. Electro Industries GaugeTech Doc E107706 V1 25 2 7 B Reactive Power VAR Total For Wye VAR VAR VAR VAR For Delta 2 n y Vas e Lact t 1 n VAR aus 2 Irus y 2 n gt Veco leo t 1 n aus el RMS y m E Apparent Power VA Total For Wye VA VA VA VA For Delta VA JW VAR B Power Factor PF For Wye x A B C T For Delta x T _ Watt VA PF Electro Industries GaugeTech Doc E107706 V1 25 2 8 IE Phase Angles Z cos PF B 7 Total Harmonic Distortion THD For Wye X VAN VBN VCN IA Ip Ic For Delta x IA Ip IC VAB VBC VCA 127 Y RMS y THD RMS x m K Factor x la Ip Ic 127 Y he RMS y KFactor Y RMS y h 1 E Watt hour Wh W Wh X H 3600 t 1 sec hr E VAR hour VARh 2 VAR A Zen t 1 sec hr Electro Industries GaugeTech Doc E107706 V1 25 2 9 2 7 Demand Integrators Power utilities take into account both energy consumption and peak demand when billing customers Peak demand expressed in kilowatts KW is the highest level of demand recorded during a set period of time called the interval The Nexus 1250 1252 supports the following most popular conventions for averaging demand and peak demand Thermal Demand Block Window Demand Rolling Window Demand and Predictive Window Demand You may program and access all conventions
3. 4RO1 4 Relay Outputs 10 Amps 125V 30V de Form C Digital Solid State Pulse Outputs Multiple modules can be used 4PO1 4 Solid State Pulse Outputs Form A KYZ pulses Digital Inputs Multiple modules can be used 8DI1 8 Digital status inputs Wet Dry Auto Detect up to 300V qc Other I O Accessories PSIO External Power Supply which is necessary if you are connecting more than 2 to 4 I O modules to a Nexus 1250 1252 Meter The number is determined by the type of I O Module MBIO Bracket for surface mounting I O modules to any enclosure G Electro Industries GaugeTech Doc E107706 V1 25 9 16 Chapter 10 Nexus Monitor with Internal Modem Option 10 1 Hardware Overview M The Nexus 1250 1252 Monitor with the INP2 Internal Modem Option has all the components of the standard Nexus Monitor PLUS the cabability of connecting to a PC via standard phone line No additional hardware is required to establish a virtually unlimited connection from a PC to a Nexus 1250 1252 with INP2 Internal Modem Option If desired the internal expansion port of the Nexus 1250 1252 can be configured with an internal 56K bps modem This gives Nexus Dial In and Dial Out capability without additional hardware This is ideal for small remote applications When the device is configured with INP2 Port 2 becomes a gateway allowing other Modbus based serial devices access to the phone line Additional connections can include a daisy chain of standard Ne
4. Potential Trf es Current Tf EE Ol Power Multiplier 0l Meter Secondary Voltage 120 120 volts for Nexus Meter Secondary Current 5 5ampsforNexus Publishing and duplicating rights are property of Electro Industries Gaugetech This spreadsheet is designed only to be used with EIG Nexus based metering equipment G Electro Industries GaugeTech Doc E107706 V1 25 Electro Industries GaugeTech Westbury NY 877 EIMETER 877 346 3837 Nexus Transformer Loss Compensation Calculation Example Three Element Meter with 3 Wye connected PT s and 3 CT s Tf Manf Trf S N AT4391 01 Loss Factors for Nx Communicator Software Calc Used No Load Loss Watts LWFE 0 04314 0 043 HV High 1380001 deta 168 224 280 XV Low 13090 we LU VV Tert WE Transformer Test Data Value 3Phase 1 Phase Calculated Calc kVA No Load Loss Watts 15400 513333 5 13 Full Load Loss Watts 6900 2306667 2307 Self Cooled kVA Rating 16800 5600 Phase to Phase Phase to Grd Test Voltage 13090 7558 Full Load Current Meter Installation Data Potential Trf 7200 120 80 1500 O 5 200 18000 Meter Secondary Voltage 120 120 volts for Nexus Meter Secondary Current 5 l 5ampsforNexus Publishing and duplicating rights are property of Electro Industries Gaugetech This spreadsheet is designed only to be used with EIG Nexus based metering equ
5. Chapter 5 Communication Wiring 5 1 Communication Overview lt lt lt lt 5 1 5 2 RS 232 Connection Nexus Meter to a Computer lt 5 5 5 3 RS 485 Wiring Fundamentals with RT Explanation lt lt 5 5 5 4 RS 485 Connection Nexus Meter to a Computer or PLC 5 8 5 5 RJ 11 Telephone Line Connection Nexus with Internal Modem Option to PC 5 8 5 6 RJ 45 Connection Nexus with Internal Network Option to multiple PC s 5 8 5 7 RS 485 Connection Nexus to an RS 485 Master Unicom or Modem Manager 5 9 5 7 1 Using the Unicom 2500 5 9 5 8 RS 485 Connectiion Nexus Meter to P40N P41N P43N External Display 5 11 5 9 RS 485 Connectiion Nexus Meter to POON External Display 5 12 5 10 Communication Ports on the Nexus I O Modules 5 13 5 11 RS 485 Connection Nexus Meter to Nexus I O Modules lt 5 14 5 12 Steps to Determine Power Needed lt 5 15 5 13 VO Modules Factory Settings and VA Ratings 5 15 5 14 Linking Multiple Nexus Devices in Series lt lt 5 16 5 15 Networking Groups of Nexus Meters lt lt 5 17 5 16 Remote Communication Overview lt lt lt 5
6. E107706 V1 25 6 1 6 2 1 Connect Multiple Displays E One cable housing two wire RS 485 and two wire power wires plus shield is used to connect the displays One port of the Nexus meter supports 12 VA Each P40N P41N or P43N requires 3 3 VA maximum 3 8 VA The Master Display P40N is the master in communication The Amp Power and Nexus devices are slaves in communication Therefore the Master Display P40N should be at the end of the daisy chained units as shown in Figure 6 2 below The Nexus port is set at 1 Protocol is Modbus RTU and Baud Rate is 9600 NEXUS UNIT P43N P41N P40N V VS B A AN V S B A V V S B A V V S B A L EA 00000 Figure 6 2 P40N Display Daisy Chain NOTE The power lines in Figure 6 2 y are shown separate for clarity All lines are actually in one cable i 59 935 A noc 2 M Shown here are diagrams of the E 58 855 n 662 H P41N and P43N Displays with c 58 HI g 560 example readings on each screen ol oa X J X Figure 6 3 PAIN Display Figure 6 4 P43N Display 6 2 2 Nexus P40N Modes E The Nexus P40N LED External Display has three modes e Dynamic Readings Mode section 6 3 and 6 4 e Nexus Information Mode section 6 5 and 6 6 e Display Features Mode section 6 7 and 6 8 M Each Mode is divided into Groups Most Groups are further broke
7. Full Load Loss VA kVA Impedance 1 Phase kVA Self Cooled Rating 100 E OHK LO OVO kVA Full Load Loss VAR KVAR SQRT Full Load Loss kVA Full Load Loss kW SQRT y dE SORT C O SQRT BE Normalize Losses to Meter Base Quantit Value at Trf M T M T Factor Ex M T Factor w Value at y Base Factor Value p Exp Meter Base persa AO TR _ No Load Loss VAR SE item e Enter Value at Transformer Base for each quantity from calculations above Enter Meter Trf Factor value from Base Conversion Factor calculations above Calculate M T Factor with Exponent by raising the M T Factor to the power indicated in the Exp or Exponent column Calculate the Value at Meter Base by multiplying the M T Factor w Exp times the Value at Trf Base E Loss Watts Percentage Values Meter Base kVA 600 PT Multiplier CT Multiplier 1000 600 1000 G Electro Industries GaugeTech Doc E107706 V1 25 7 7 m Calculate Load Loss Values Quantit Value at Meter Meter Base Loss at Quant y Base kVA Meter Base y No Load Loss kW Loss Watts FE Loss Watts CU Loss VARs CU Load Loss kW Load Loss kVAR Enter Value at Meter Base from Normalize Losses section Enter Meter Base kVA from previous calculation Calculate Loss at Meter Base by dividing Value at Meter Base by Meter Base kVA and multiplying by 100 Enter calculated Loss W
8. Overview The KYZ Pulse Output Modules have 4 KYZ Pulse Outputs and accept Read and Write Commands with at least 4 registers of data per command Digital Solid State Pulse Output KYZ Modules are user programmed to reflect VAR hours WATT hours or VA hours See the Modbus Communicating 1 0 Modules User Manual for details on programming the module Nexus 1250 1252 Unit supplies power for up to 4 connected KYZ Pulse Output modules See section 9 2 for power and communication details Refer to sections 5 12 5 13 to determine if you must use an additonal power source such as the EIG PSIO The Modbus Map for the KYZ Pulse Output Module and operating details can be found in the Modbus Communicating I O Modules Manual NC Normally Closed NO Normally Open C Common Electro Industries GaugeTech Doc E107706 V1 25 9 13 9 8 2 Communication E Maximum registers per request read or write is 4 registers orm BE The device will operate with the following Default Mode Parameters See section 9 4 1 for details Address 247 F7H Baud Rate 57600 Baud Transmit Delay Time 20 csec 9 8 3 Normal Mode M Energy readings are given to the device frequently The device generates a pulse at each channel after a certain energy increase E Normal Operation consists of three processes 1 The first process accepts writes to registers 04097 04112 Writes can be up to four registers long and should end on the fourth register of a group regis
9. Reset Button RESETS LIMITS SETTINGS View Limits View Change Settings Figure 6 2 Nexus P60N Touch Screen External Display Main Screen E GENERAL PAGE Overview of Real Time Eee PACA PRE Readings READINGS DETAILS Kb e Volts AN BN CN AB BC CA Deel Amps A B C CN 12282 e Watts e VARS k e VA e FREQ e PF POLLING MAIN G Electro Industries GaugeTech Doc E107706 V1 25 6 10 E VOLTS Voltage Readings Details VOLTAGE READINGS DETAILS e Real Time Volts AN BN CN AB BC CA e Maximum Volts AN BN CN AB BC CA ne SE ie e Minimum Volts AN BN CN AB BC CA A N 123 04 234 85 0 00 B N 123 05 263 84 0 00 Touch PH N or PH PH to view details of SE de au ben Phase to Neutral or Phase to Phase Readings A B 0 00 80 14 0 00 B C 0 00 88 00 0 00 C A 0 00 18 08 0 00 POLLING MAIN NEXT PH N oc REAL TIME VOLTAGE E VOLTS Voltage Readings PH N READINGS DETAILS e Volts AN BN CN VOLTS Touch BACK to return to the Volts main screen A N 121 72 B N 121 70 C N 121 72 REAL TIME VOLTAGE E VOLTS Voltage Readings PH PH READINGS DETAILS e Volts AB BC CA VOLTS Touch BACK to return to the Volts main screen AB 0 0000 B C 0 0000 C A 0 0000 POLLING MAIN NEXT CURRENT E AMPS Current Readings Details READINGS DETAILS e Real Time Current A B C REAL TIME MAX e Maximum Current A B C AMES AMPS e Minimum Current A B C o pes e Current Calculated N Measur
10. energy and demand without differentiating between the three Because this practice can lead to confusion the differences between these three measurements will be discussed M Power is an instantaneous reading The power reading provided by a meter is the present flow of watts Power is measured immediately just like current In many digital meters the power value is actually measured and calculated over a one second interval because it takes some amount of time to calculate the RMS values of voltage and current But this time interval is kept small to preserve the instantaneous nature of power IE Energy is always based on some time increment it is the integration of power over a defined time increment Energy is an important value because almost all electric bills are based in part on the amount of energy used E Typically electrical energy is measured in units of kilowatt hours kWh A kilowatt hour represents a constant load of one thousand watts one kilowatt for one hour Stated another way if the power delivered instantaneous watts is measured as 1 000 watts and the load was served for a one hour time interval then the load would have absorbed one kilowatt hour of energy A different load may have a constant power requirement of 4 000 watts If the load were served for one hour it would absorb four kWh If the load were served for 15 minutes it would absorb 4 of that total or one kWh E Figure 1 7 shows a graph of power and the re
11. terminal The S terminal on the Nexus 1250 1252 is used to reference the Nexus port to the same potential as the source It is not an earth ground connection You must also connect the shield to earth ground at one point e Provide termination resistors at each end connected to the A and B lines RT is approximately 120 Ohms NOTE Refer to section 5 3 for RT Explanation A BOS V Nexus Meter Port 4 UUI V S BOAH Figure 5 13 Nexus Meter Connected to Nexus l O Module Electro Industries GaugeTech Doc E107706 V1 25 5 14 5 12 Steps to Determine Power Needed Available power for All Ports of the Nexus 1250 1252 is 12 VA Refer to the table below to determine the VA Ratings for I O modules and displays Add together the VA Ratings for Os and Displays in use Compare Available Power to Power Needed to determine if you must use an additional power source EIG recommends the PSIO 12V power source See section 9 2 1 5 13 1 0 Modules Factory Settings and VA Ratings M All VOsare shipped pre programmed with a baud rate of 57600 and addresses The table below details the factory set address for each module and the VA Ratings for I O modules and Nexus displays Refer to the previous section section 5 12 for the steps to determine if you must use an additional power source For programming refer to Chapter 8 of the Communicator EXT User Manual HO MODULES FACTORY SETTINGS AND VA RATINGS MODEL NUMBE
12. 18 5 17 Remote Communication RS 232 5 21 5 18 Remote Communication RS 485 lt lt 5 21 5 19 Programming Modems for Remote Communication 5 22 5 20 Selected Modem Strings lt 5 23 5 21 High Speed Inputs Connection lt lt 5 23 5 22 Five Modes of Time Synchronization lt lt lt lt 5 24 5 23 IRIG B Connections lt lt 5 25 Chapter 6 Using the Nexus External Displays 6 13 OV rvi W bah GE Bat kl de Boab A he Pe v obed ly de LE M 6 1 6 2 Nexus P40N DAIN P43N LED External Display lt 6 1 6 2 1 Connect Multiple Displays lt lt lt 6 2 6 22 Nexus PAON Modes ovinte fus dog tu aie Ji be lesk u n v boky pute du 6 2 6 3 Dynamic Readings Mode 6 3 6 4 Navigational Map of Dynamic Readings Mode lt 6 5 6 5 Nexus Information Mode lt lt lt lt 6 6 6 6 Navigational Map of Nexus Information Mode 6 7 6 7 Display Features Mode lt lt lt 6 8 6 8 Navigational Map of Display Features Mode 6 9 6 9 Nexus P60N Touch Screen
13. 2004 15 30 00 13 MIN VOITS A 04 20 2004 09 30 00 12 s Min Volts A B C MIN VOLTS B 04 30 2004 09 30 00 12 MIN VOLTS 04 30 2004 09 30 00 12 Touch INST or LONG TERM to view screens SIAIUS Stopped START or STOP will appear depending on Status e INST IZ Gr MAIN G Electro Industries GaugeTech Doc E107706 V1 25 6 13 E FLICKER LONG TERM e Volts A B C e Max Volts A B C e Min Volts A B C Touch INST or LONG TERM to view other Flicker screens START or STOP will appear depending on Status B LIMITS Limit Status Current Limits Settings for Nexus Meters ID 1 32 For each ID number the Type of Reading Value Status In or Out of Limit and Setting is shown The first screen displays the settings for Meters ID 1 to 8 Touch NEXT GROUP to scroll to the next screen which displays the settings for Meters ID 9 to 16 Touch NEXT GROUP again to view settings for Meters ID 17 to 24 and 25 to 32 E PHASORS Phasor Analysis Phase Angles for Form shown at top of the screen Phase Phase Angle Van bn cn Phase Angle Ia b c Phase Angle Vab bc ca E WAVEFORM Real Time Graph Channel Va b c Channel la b c e THD KFactor Frequency for selected channel Touch CHANNEL button to view scroll through channels FLICKER LONG TERM 1 16 05 3 52 Pm PST TIME VOLTS A 0 000 00 00 0000 00 00 00 00 VOLTS B 0 000 00 00 0000 00 00 00 00 VOLIS C 0 000 00 00 0000 00 00 00 00 MAX VOITS A 9 339 06
14. Binary Block Window Avg Power Electro Industries Gauge Tech Doc E107706 V1 25 Glossary These values are the RMS values of the indicated guantity as calculated after approximately 50 milliseconds 3 cycles of sampling These values are the RMS values of the indicated guantity as calculated after one second 60 cycles of sampling An event or condition in a meter that can cause a trigger or call back to occur A short label that identifies particular guantities or values displayed for example kWh When applied to current values amps the average is a calculated value that corresponds to the thermal average over a specified time interval The interval is specified by the user in the meter profile The interval is typically 15 minutes So Average Amps is the thermal average of amps over the previous 15 minute interval The thermal average rises to 90 of the actual value in each time interval For example if a constant 100amp load is applied the thermal average will indicate 90 amps after one time interval 99 amps after two time intervals and 99 9 amps after three time intervals When applied to Input Pulse Accumulations the Average refers to the block fixed window average value of the input pulses When applied to power values watts VARs VA the average is a calculated value that corresponds to the thermal average over a specified time interval The interval is specified by the user in the meter profile T
15. Computer Name Click OK 3 If you are NOT using DHCP in the Network Settings section enter data provided by your systems manager IP Address 10 0 0 1 Example Subnet Mask 255 255 255 0 Example Default Gateway 0 0 0 0 Example Computer Name NETWORK Example IE Enter the Domain Name Server and Computer Name M Customize Web Content if desired Default Pages with an extensive array of readings comes with the meter The content of the pages can be customized using FTP Client From the Device Profile Communications Ports screen click Advanced Settings Click the FTP Client tab on the top of the folder Using FTP you can easily replace any file by using the SAME FILE NAME as the one you want to replace M Enter the Email Server IP Address The Default Settings store ONE Email Server IP Address for administrative purposes or to send an alarm if there is a problem An ADDITIONAL 8 can be con figured with FTP Client BE Update FIRMWARE if needed with TFTP protocol see Appendix C M After the above parameters are set Communicator EXT will connect via the network using a Device Address of 1 and the assigned IP Address using the following steps 1 Double click on Communicator EXT icon to open 2 Click the Connect icon in the icon tool bar The Connect screen will appear 3 Click the Network button at the top of the screen The screen will change to one requesting the following information Device Address 1
16. Display AAD RUN TIME 606 DSP BOOT 600 DSP RUN TIME 604 LCD DISPLAY AAD This screen displays the current firmware version for the Nexus and the display NEXT G Electro Industries GaugeTech Doc E107706 V1 25 6 17 6 10 Navigational Map for P60N Touch Screen External Display AMPS Current Readings Details Real Time Power Readings Details Demand Power Readings Details NEXT Current Voltage Readings NEXT Readings A B C MN Voltage PH PH Readings PH N A B C BACK PH PH BACK VOLTS Voltage Readings Details AMPS VOLTS REAL TIME POWER Accumulated Energy MA Information e FLICKER TOU NEXT X Time of Use Readings Register yA Accumulations A LONG DEMAND NEXT ACCUM TERM k Time of Use 7 Readings Instantaneous Register NEXT Flicker SHORT Demand TERM Long Time Flicker General Page Meter Reset Commands GENPAGE RESETS SETTINGS LOG STATUS MAIN TREND WAVEFORM LIMITS PHASORS Ta Status Port Settings NEXT NEXT NEXT Firmware Versions Link Settings NEXT LCD Screen Settings NEXT Log Status N Real Time Trending Table NEXT BACK ye DETAIL Real Time Trending Graph CHANNEL OK SPECTRUM NEXT e Real Time Trending Selector CE S
17. E107706 V1 25 9 8 9 6 Analog Input Modules Analog Input Modules Specifications 8AI1 8 Channel Analog Input O 1mA 8AI2 8 Channel Analog Input 0 20mA Model Numbers SAI3 8 Channel Analog Input 0 5V 4c 8AI4 8 Channel Analog Input 0 10V 4c RS 485 Modbus RTU Communication Programmable Baud Rates 4800 9600 19200 57600 15 20V q at 50 200mA Power Reguirement Nexus 1250 1252 Unit supports up to 4 Modules Operating Temperature 20 to 79 C 4 to 158 F 0 ImA WE 4 20mA 500 Impedance Modbus Address 8AI1 0 1mA 136 8AI2 0 20mA 140 SAI3 045 V ic 144 SA GIOUN gc 148 Baud Rate 57600 Transmit Delay Time 0 Modbus Address 247 Factory Settings Default Settings Reset Button Baud Rate 57600 Transmit Delay Time 20 csec 9 6 1 Overview The Analog Input Modules 0 1mA 0 20mA 0 5V gc and 0 10V are available in 8 channel format Maximum registers per request read or write is 17 registers Nexus 1250 1252 Unit supplies power for up to 4 connected Analog Input modules See section 9 2 for power and communication details Refer to sections 5 12 5 13 to determine if you must use an additonal power source such as the EIG PSIO All inputs share a single common point This is also an isolated connection from ground Electro Industries GaugeTech Doc E107706 V1 25 9 9 M The Modbus Map for the Analog Output Module and operating details can be found in the Modbus Communicatin
18. External Display 6 10 6 10 Navigational Map for POON Touch Screen External Display 6 18 Chapter 7 Transformer Loss Compensation l Introduction ds 4 tke ho ok ite ee di dk A de mu den 7 1 7 2 Nexus 1250 1252 Transformer Loss Compensation 7 3 7 2 1 Loss Compensation in Three Element Installations 7 4 7 2 1 1 Three Element Loss Compensation Worksheet 7 5 Chapter 8 Nexus Time of Use 8 1 Introduction 2 42 42545 4 4 Li be Re ce a ae n BA 8 1 8 2 The Nexus TOU Calendar 8 1 G Electro Industries GaugeTech Doc E107706 V1 25 vi 8 3 TOU Prior Season and Month e 8 2 8 4 Updating Retrieving and Replacing TOU Calendars 8 2 8 5 Daylight Savings and Demand lt lt lt lt 8 2 Chapter 9 Nexus External VO Modules 9 1 Hardware Overview 9 1 91 15 Port Overview ME 8 dock Ri dn a Bd e Bou a ion M A A 9 2 9 2 Installing Nexus External I O Modules lt 9 3 9 2 1 Power Source for I O Modules 9 4 9 3 Using PSIO with Multiple I O Modules lt 9 5 9 3 1 Steps for Attaching Multiple I O Modules 9 5 9 4 Factory Settings and Rese
19. G Electro Industries GaugeTech Doc E107706 V1 25 Chapter 2 Nexus Overview 2 1 The Nexus System Electro Industries Nexus 1250 1252 combines high end revenue metering with sophisticated power quality analysis Its advanced monitoring capabilities provide detailed and precise pictures of any metered point within a distribution network The P60N P40N P41N and P43N displays are detailed in Chapter 6 Extensive O capability is available in conjunction with all metering functions The optional Communicator EXT software allows a user to poll and gather data from multiple Nexus meters installed at local or remote locations see the Communicator EXT User Manual for details On board mass memory enables the Nexus to retrieve and store multiple logs The Nexus Meter with Internal Modem or Network Option connects to a PC via standard phone line or MODBUS TCP and a daisy chain of Nexus Meters via an RS 485 connection See Chapters 10 and 11 for details Modem Ethernet Option Modem Gateway or Ethernet Gateway Computer c or SCADA RS 485 Connection Expandable UO Modules Nexus u kaft ke Display rn 100080 e e as Modem Ethernet 000 000 000 000 Option Nexus Meter RJ 11 or RJ 45 Connection esoo e D ic M BEES CECR Figure 2 1 The Nexus 1250 1252 System Electro Industries GaugeTech Doc E107706 V1 25 2 1 E Nexus 1250 1252 Revenue Metering Delivers laboratory grade 0 04 Watt hour accuracy in a field mou
20. LEAD DEMAND 14658 POLLING MAIN NEXT DEMAND POWER READINGS DETAILS THERMAL BLOCK ROLLING tKWATTS 9 8 9 8 9 1 KWATTS 6553 6 6553 6 6553 6 WATTS 14 7 14 7 12 1 Coin KVars WATTS Coin KVars KVAHS KVARS POLLING MAIN NEXT ACCUMULATED ENERGY INFORMATION 0 0 0 0 0 0 6553 6 16 9 VAR 000000000000000 VA O00000000000000 VAR 00000000000000000 VA oooo00000000000 DEL WATT 00000000000000702 VA DODOD00000000000 VAR O000000000000000 REC WATT 0000000088070247 VA 000000000061221713 VAR 000000000012217891 JPornnge NEXT B TOU Accumulations TIME Or USE READINGS di DH M REGISTER ACCUMULATIONS Watthr Quadrant 2 Quadrant 3 Primary 01 05 05 00 00 00 08 04 05 23 59 59 VAhr Quadrant 2 Primary VAR 00000000000000000 VAR 000000000011816 VARhr Quadrant 2 Primary VA 900000000000000 VA 000000000096221 VAhr Quadrant 3 Primary 92101 ec watt 9 00000000000000001 Q3 DA 0000000010170247 VARhr Quadrant 3 Primary Watthr Quadrant 1 Quadrant 4 Primary VA D000000000012026 VA 000000000011221713 VAhr Quadrants 1 amp 4 Primary VARhr Quadrant 4 Primary SS REGISTER TOTALS DEMAND cuRRENT NEXT Touch DEMAND to view Register Demand screen pemano gege UE Touch Next Reg to scroll Registers 1 8 and Totals VAR 0000000000000198 VAR 000000000012217891 y TIME OF USE READINGS c Touch Next Group to scroll Prior Season Prior REG
21. M Externally fuse the power supply with a 5 Amp fuse 4 8 Wiring Diagrams E Choose the diagram that best suits your application Diagrams appear on the following pages If the connection diagram you need is not shown contact EIG for a custom Connection diagram E NOTE If you purchased a G Option Nexus for a 300 Volt secondary be sure to enable the option on the CT and PT screen of the Communicator EXT software s Device Profile see the Communicator EXT User Manual for details Figures Description G Electro Industries GaugeTech Doc E107706 V1 25 4 3 000 000 000 000 LINE gt CT SPORTING Ey SWITC D J D o S o el o SA SE LT let z p SWITCHGEAR CHASSIS O GROUND 0 25 A L DEPENDENT EN EQUIPPED POWER SUPPLY OPTION NCBA LOAD Figure 4 1 4 Wire Wye 3 Element Direct Voltage with 4 CTs G Electro Industries GaugeTech Doc E107706 V1 25 000 000 000 000 LINE CT SHORTING SMTCH x ST BLOCK 2 2 2 gt o B O SWITCHGEAR CHASSIS GROUND 0 25A SUPPLY POWER INPUT L DEPENDENT ON EQUIPPED POWER SUPPLY OPTION NCBA LOAD Figure 4 2 4 Wire Wye 3 Element with 3 PTs and 4 CTs G Electro Industries GaugeTech Doc E107706 V1 25 ODO 000 000 00 crass veux Yrer LINE 9 Lu oe BE DEE CT SHORTING SMTCH 5 OR TESE BLOCK E Ki j E s R A NSR KE el F Et Deeg SSES E SE E EN 0 25 A 4 LN p
22. RT is approximately 120 Ohms but this value may vary based on length of cable run gauge or the impedance of the wire NOTE Refer to section 5 3 for RT Explanation Up to 31 Nexus 1250 1252 Meters Maximum RS 485 to RS 232 Converter RS 485 Master Nexus RS 485 Port Nexus RS 485 Port GND TX RX TX RX V S B A V S Bl A V S B A Figure 5 14 Linking Multiple Nexus Devices in Series G Electro Industries GaugeTech Doc E107706 V1 25 5 16 5 15 Networking Groups of Nexus Meters IE You may connect up to 31 Nexus 1250 1252 Meters on the same RS 485 bus Each one must be assigned a unique address see the Communicator EXT User Manual Use an RS 485 repeater to network several links of instruments E A maximum number of 31 Nexus 1250 1252 Meters may be connected to one repeater A maximum number of 31 repeaters may be included on the same network Maximum 31 Nexus 1250 1252 Meters RS 485 Maximum 31 Repeaters REPEATER Maximum 31 Nexus Meters RS 485 RS 485 232 Converter jl Figure 5 15 Networking Groups of Nexus Meters G Electro Industries GaugeTech Doc E107706 V1 25 5 17 5 16 Remote Communication Overview M Use modems dedicated or dial up when devices are at great distances EIG recommends using RS 485 wiring with a Modem Manager See section 5 13 Remote Connection RS 232 PC at office Local PSTN Public Remote Nexus 1250 1252 Modem Switched Modem Meter Teleph
23. Refer to the Communicator EXT Software Manual for programming details G Electro Industries GaugeTech Doc E107706 V1 25 10 2 Chapter 11 Nexus Meter with Internal Network Option 11 1 Hardware Overview M The Nexus 1250 1252 Meter with the Internal Network Option has all the components of the standard Nexus Meter PLUS the cabability of connecting to a multiple PC s via Modbus TCP over Ethernet Additional hardware is not required to establish a connection from a network to a Nexus with Internal Network Option With the Internal Network Option the Nexus 1250 1232 provides an Ethernet Gateway allowing access to other Modbus RTU devices Additional connections can include a daisy chain of standard Nexus Meters A daisy chain can include up to 31 meters If more are desired the installation of a repeater allows additional meters See section 5 15 for repeater details RS 485 MODBUS RTU 10 100BaseT or 10BaseT RJ 45 MODBUS TCP WL over Ethernet NEXUS 1250 OEM Del g a Del COCOCOCO IS NS Network Figure 11 1 Nexus with Internal Network Option G Electro Industries GaugeTech Doc E107706 V1 25 11 1 M The Internal Network Option of the Nexus Meter is an extremely versatile communications tool Adheres to IEEE 802 3 ethernet standard using TCP IP Utilizes simple and inexpensive 10 100BaseT wiring and connections Plugs right into your network using built in RJ 45 jack Programmable to any IP
24. SUPPLY POWER INPUT NCBA Lt DEPENDENT ON EQUIPPED POWER SUPPLY OPTION LOAD Figure 4 3 4 Wire Wye 3 Element with 3 PTs and 3 CTs G Electro Industries GaugeTech Doc E107706 V1 25 IMPORT 000 000 000 000 EXPORT LINE CT_SHORTING SWITCH H OR TEST BLOCK Y In Lo SE o o O A P SWITCHGEAR CHASSIS GROUND PTs 0 25 A SESCH SUPPLY POWER INPUT L DEPENDENT ON EQUIPPED POWER SUPPLY OPTION GBA Figure 4 4 3 Wire 2 Element Open Delta with 2 PTs and 3 CTs G Electro Industries GaugeTech Doc E107706 V1 25 4 7 ooo 000 000 000 LINE CT l SHIRTING SKICH SEET SWI dio cil PTs 0 25 A MZ SUPPLY POWER INPUT L DEPENDENT UN EQUIPPED POWER SUPPLY OPTION C B A LOAD Figure 4 5 3 Wire 2 Element Open Delta with 2 PTs 2 CTs G Electro Industries GaugeTech Doc E107706 V1 25 000 000 000 000 LINE CT SHORTING SWITCH OR TEST BLOCK SWITCHGEAR CHASSIS GROUND 0 25 A yo SUPPLY POWER INPUT L DEPENDENT ON EQUIPPED POWER SUPPLY OPTION C B A Figure 4 6 3 Wire 2 Element Delta Direct Voltage with 3 CTs G Electro Industries GaugeTech Doc E107706 V1 25 4 9 000 000 000 000 LINE CT SHORTING SMTCH x OR TEST BLOCK 2 7 Hi o Gem GES ag SE Ges o SWITCHGEAR CHASSIS E En El ES KE GROUND Figure 4 7 3 Phase 4 Wire Wye 2 5 Element with 2 PTs 3 CTs 0 25 A _ SUPPLY POWER INPUT L DEPENDENT ON EQUIPPED POW
25. connect to another module s male RS 485 side port E I O Port use for functions specific to the type of module size and pin configuration varies depending on type of module For more detail refer below to section 5 11 and to Chapter 9 of this manual Mounting Brackets Female RS 485 Side Port VO Port Size and pin configuration vary Male RS 485 Side Port Figure 5 12 Communication Ports on the Nexus l O Modules G Electro Industries GaugeTech Doc E107706 V1 25 5 13 5 11 RS 485 Connection Nexus Meter to Nexus 1 0 Modules M Six feet of RS 485 cable harness is supplied Insert one end of the cable into Port 4 of the Nexus 1250 1252 Meter M Insert the other end of the cable into the I O modules female RS 485 side port see Figure 5 9 The connectors fit only one way into the ports M Use the male RS 485 side port to attach another I O module The Nexus 1250 1252 will power up to four connected I O modules using 15 20V DC at 50 200mA represented by dashed lines in the figure below Use the steps below section 5 12 to determine 1f you must use a separate power source for example EIG PSIO to supply added power to the group RS 485 communication is viable for up to 4000 feet 1219 meters However if your cable length exceeds 200 feet use the remote power supply and e Connect the A and B terminals on the Nexus to the A and B terminals of the female RS 485 port Connect the shield to the shield S
26. for a period of time typically from 1 2 cycle to 1 minute Any Register or pulse output that does not use any CT or VT Ratio The type of port used to directly interface with a PC In Modbus communication a Slave Device only receives a Request Packet from a Master Device and responds to the request A Slave Device cannot initiate communication A voltage quality event during which the RMS voltage is higher than normal for a period of time typically from 1 2 cycle to 1 minute Total Harmonic Distortion is the combined effect of all harmonics measured in a voltage or current The THD number is expressed as a percent of the fundamental For example a 3 THD indicates that the magnitude of all harmonic distortion measured equals 3 of the magnitude of the fundamental 60Hz guantity Glossary 5 Time Stamp A stored representation of the time of an event Time Stamp can include year month day hour minute and second and Daylight Savings Time indication TOU Time of Use Voltage Imbalance The ratio of the voltage on a phase to the average voltage on all phases Voltage Quality Event An instance of abnormal voltage on a phase The events the meter will track include sags swells interruptions and imbalances VT Ratio The Voltage Transformer Ratio is used to scale the value of the voltage to the primary side of an instrument transformer Also referred to as PT Ratio Voltage Vab Vab Vbc Vca are all Phase to Phase voltage measu
27. of 9600 To use a port other than Port 3 you must set the port s baud rate to 9600 using the Communicator EXT software see the Communicator EXT User Manual Insert the other end of the cable into the back of the Nexus P40N P41N or P43N Display The connectors fit only one way into the ports M The cable harness brings 17V DC to the displays from the Nexus 1250 1252 Meter represented by dashed lines in the figure below RS 485 communication is viable for up to 4000 feet 1219 meters If your cable length exceeds 200 feet you must use a remote power supply such as EIG s PSIO and e Connect the shield to the shield S terminal on the Nexus Display port The S terminal on the Nexus is used to reference the Nexus port to the same potential as the source Itis not an earth ground connection You must also connect the shield to earth ground at one point e Provide termination resistors at each end connected to the A and B lines RT is approximately 120 Ohms NOTE Refer to section 5 3 for RT Explanation Nexus P40N P41N or P43N Display Port A BO S V Nexus P40N P41N or P43N Display Back View Top Bottom ed Nexus Meter Port 3 V S BC A Figure 5 10 Nexus Meter Connected to Nexus P40N P41N or P43N External Display G Electro Industries GaugeTech Doc E107706 V1 25 5 11 5 9 RS 485 Connection Nexus Meter to the Nexus P60N External Display M To connect the Nexus P60N Touch Screen External Display
28. one single meter Today with the Nexus 1250 1252 1262 1272 and the Shark EIG is a leader in the development and production of power monitoring products All EIG products are designed manufactured tested and calibrated at our facility in Westbury New York Applications Multifunction power monitoring Single and multifunction power monitoring Power quality monitoring On board data logging for trending power usage and quality Disturbance analysis Futura Series Products Power quality monitoring High accuracy AC metering On board data logging On board fault and voltage recording DM Series Products Three phase multifunction monitoring Wattage VAR and amperage Modbus Modbus Plus DNP 3 0 and Ethernet protocols Analog retransmit signals 0 1 and 4 20mA Single Function Meters AC voltage and amperage DC voltage and amperage AC wattage Single phase monitoring with maximum and minimum demands Transducer readouts Portable Analyzers M Power quality analysis M Energy analysis G Electro Industries GaugeTech Doc E107706 V1 25 II G Electro Industries GaugeTech Doc E107706 V1 25 Table of Contents Chapter 1 Three Phase Power Measurement 1 1 Three Phase System Configurations lt lt lt 1 1 1 1 1 Wye Connnection 1 1 1 1 2 Delta Connection lt lt lt lt 1 3
29. system operating at 60Hz Flicker will still operate but the values computed will not be valid Select carefully User settings are stored If Flicker is on and power is removed from the meter Flicker will still be on when power returns This can cause data gaps in the logged data The Max and Min values are stored and are not lost if the unit is powered down Flicker meets the requirements of IEC 61000 4 15 and former IEC 868 Refer to those specifications for more details if needed Operation is at 230V for 50Hz and 120V for 60Hz as per specification If the input voltage is different the system will normalize it to 230V or 120V for computational purposes G Electro Industries GaugeTech Doc E107706 V1 25 12 8 Appendix A Transformer Loss Compensation Excel Spreadsheet with Examples A 1 Calculating Values M Transformer Loss Compensation is discussed in Chapter 7 of this manual Values for three element installations can be calculated in two ways e Click the TLC Calculator button on the Transformer Loss screen of the Nexus Device Profile The TLC Calculator button activates an Excel Spreadsheet ONLY if you have MS Excel installed on your computer A copy of the Excel Spreadsheet is offered on the following pages with example numbers 1 Enter the required data into the Excel Spreadsheet The Excel program will calculate the values needed for the Transformer Loss screen of the Device Profile 2 Enter the values into the D
30. the Internal Network Option has a unique label Port 2 is labeled Ethernet Gateway If you are going to use RS 485 to connect multiple Nexus meters via the net work you MUST use the Ethernet Gateway For more details see Chapter 11 of this manual RS 485 MODBUS RTU 10 100BaseT or 10BaseT RJ 45 MODBUS TCP over Ethernet LU VU o 000 000 000 000 Fee IM NN Network Figure 5 3 RJ 45 Communication with Internal Network Option Electro Industries GaugeTech Doc E107706 V1 25 5 3 For all communications S Shield This connection is used to reference the Nexus port to the same potential as the source It is not an earth ground connection You must also connect the shield to earth ground at one point I O Modules and Display reguire power connections to the voltage terminals dashed lines RS 232 Extension Cable 1 to 1 wiring RS 485 Master Unicom or Modem Manager Nexus P40N External Display Nexus I O Module 0 Ohms 120 Ohms r OLD LX gt V TD RT l l l l l 120 Ohms 120 Ohms 120 Ohms o 0 00000 V S BC A V SBOAH V SBOAM V SBOAH 8 7 654 3210 Port 1 Port 2 Port Port 4 High Speed Inputs IRIG B RS 232 or Normally Slave RS 485 Set Modem Ethernet Gateway RS 232 RS 485 NOTE You may use ANY port to connect a Nexus Display or RS 485 Master Ho
31. through the gateway and become a virtual connection between the Remote Modbus Master and any Modbus Slave connected to the RS 485 Gateway 2 4 2 Dial In Function IE The modem continuously monitors the telephone line to detect an incoming call When an incoming call is detected the modem will wait a user set number of rings and answer the call IE The modem can be programmed to check for a password on an incoming call If the correct password is not provided the modem will hang up on the incoming call If several unsuccessful incoming call attempts are received in a set time period the modem will lock out future incoming calls for a user set number of hours E When an incoming call is successfully connected the control of communications is passed to the calling software program The modem will respond to computer commands to download data or other actions authorized by the meter passwords Refer to the Communicator EXT Software Manual for instructions on programming the modem 2 4 3 Dial Out Function B The Dial Out Function INP2 is intended to allow the meter to automatically report certain conditions without user intervention The modem is normally polling the meter to determine if any abnormal or reportable conditions exist The modem checks programmed meter conditions and programmed events set in Nexus Communicator to determine if a call should be placed If any of the monitored events exist the modem will automatically initiate
32. to download data or perform other actions authorized by the meter passwords 10 4 Dial Out Function E The Dial Out Function is intended to allow the meter to automatically report certain conditions without user intervention The modem is normally polling the meter to determine if any abnormal or reportable conditions exist The modem checks the following meter conditions and programmed events set in Nexus Communicator to determine if a call should be placed Are any meter set point limits exceeded Has status of high speed inputs changed Has waveform been recorded Has power quality event been recorded Has a control output changed Is either history log approaching a full condition Is the event log approaching a full condition Is any other log approaching a full condition Has the Modem Password failed Has Communication with the Nexus failed E If any of the monitored events exist the modem will automatically initiate a call to a specified location to make a report or perform some other function For log full conditions the meter will automatically download the log s that are nearing the full state The modem can be programmed to call two different numbers to make the required reports Primary and Backup M The modem can be programmed with an ASCII string for identification purposes If this string is present the modem will play the string to the host computer upon connection to identify the meter to the host software
33. using RTs 5 7 1 Using the Unicom 2500 The Unicom 2500 provides RS 485 RS 232 conversion In doing so it allows the Nexus to communicate with a PC or other device See the Unicom 2500 Installation and Operation Manual for additional information Figures 5 8 and 5 9 on the next page illustrate the Unicom 2500 connections for RS 485 G Electro Industries GaugeTech Doc E107706 V1 25 5 9 RS232 Port UNICOM 2500 Fiber Optic RX TX RX RS232 Port TX RX TX RX GNO UNICOM 2500 Jumpers Short TX to RX to make terminal Fiber Optic Short TX to RX to RS 485 make terminal RX TX TX RX TX RX_ GN Twisted Pair Shielded Cable A 8 Figure 5 9 Detail of Jumpers Figure 5 8 Unicom 2500 with Connections The Unicom 2500 can be configured for either 4 wire or 2 wire RS 485 connections Since the Nexus uses a 2 wire connection you need to add jumper wires to convert the Unicom 2500 to the 2 wire configuration As shown in Figure 5 9 you connect the RX and TX terminals with a jumper wire to make the terminal and connect the RX and TX terminals with a jumper wire to make the terminal G Electro Industries GaugeTech Doc E107706 V1 25 5 10 5 8 RS 485 Connection Nexus Meter to the Nexus P40N External Display M Insert one end of the supplied RS 485 cable into Port 3 of the Nexus 1250 1252 Meter Port 3 is factory set to match the Nexus Display s baud rate
34. were taken C gt B gt Phase B Phase C 2 O D Node n A Phase A gt Figure 1 6 Three Phase Wye Load illustrating Kirchhoff s Law and Blondell s Theorem Blondell s Theorem is a derivation that results from Kirchhoff s Law Kirchhoff s Law states that the sum of the currents into a node is zero Another way of stating the same thing is that the current into a node connection point must equal the current out of the node The law can be applied to measuring three phase loads Figure 1 6 shows a typical connection of a three phase load applied to a three phase four wire service Krichhoff s Laws hold that the sum of currents A B C and N must equal zero or that the sum of currents into Node n must equal zero If we measure the currents in wires A B and C we then know the current in wire N by Kirchhoff s Law and it is not necessary to measure it This fact leads us to the conclusion of Blondell s Theorem that we only need to measure the power in three of the four wires if they are connected by a common node In the circuit of Figure 1 6 we must measure the power flow in three wires This will require three voltage coils and three current coils a three element meter Similar figures and conclusions could be reached for other circuit configurations involving delta connected loads G Electro Industries GaugeTech Doc E107706 V1 25 1 5 1 2 Power Energy and Demand E tis quite common to exchange power
35. with one phase in common In a three phase four wire wye system it is necessary to use three elements Three voltage coils are connected between the three phases and the common neutral conductor A current coil is required in each of the three phases In modern digital meters Blondell s Theorem is still applied to obtain proper metering The difference in modern meters is that the digital meter measures each phase voltage and current and calculates the single phase power for each phase The meter then sums the three phase powers to a Electro Industries GaugeTech Doc E107706 V1 25 1 4 single three phase reading Some digital meters calculate the individual phase power values one phase at a time This means the meter samples the voltage and current on one phase and calculates a power value Then it samples the second phase and calculates the power for the second phase Finally it samples the third phase and calculates that phase power After sampling all three phases the meter combines the three readings to create the equivalent three phase power value Using mathematical averaging techniques this method can derive a quite accurate measurement of three phase power More advanced meters actually sample all three phases of voltage and current simultaneously and calculate the individual phase and three phase power values The advantage of simultaneous sampling 1s the reduction of error introduced due to the difference in time when the samples
36. 0 Intervals gt Figure 1 8 Energy Use and Demand M As can be seen from this example it is important to recognize the relationships between power energy and demand in order to control loads effectively or to monitor use correctly 1 3 Reactive Energy and Power Factor M The real power and energy measurements discussed in the previous section relate to the quantities that are most used in electrical systems But it is often not sufficient to only measure real power and energy Reactive power is a critical component of the total power picture because almost all real life applications have an impact on reactive power Reactive power and power factor concepts relate to both load and generation applications However this discussion will be limited to analysis of reactive power and power factor as they relate to loads To simplify the discussion generation will not be considered M Real power and energy is the component of power that is the combination of the voltage and the value of corresponding current that is directly in phase with the voltage However in actual practice the total current is almost never in phase with the voltage Since the current is not in phase with the voltage 1t is necessary to consider both the inphase component and the component that is at quadrature angularly rotated 90 or perpendicular to the voltage Figure 1 9 shows a single phase voltage and current and breaks the current into its in phase and quadr
37. 00 177 8 Figure 3 6 Cutout for Nexus P60N Touch Screen Display M To bezel mount the P6ON cut an opening in the mounting panel Follow above cutout dimensions M Carefully drop in the P6ON with bezel and gasket attached M Fasten the unit securely with the four 6 32 hex nuts supplied G Electro Industries GaugeTech Doc E107706 V1 25 3 5 3 4 Mounting the Nexus External UO Modules M Secure the mounting brackets to the I O using the screws supplied 440 pan head screws Next secure the brackets to a flat surface using a 8 screw with a lock washer E If multiple I O modules are connected together as shown in Figure 3 4 secure a mounting bracket to both ends of the group One Nexus will supply power for up to four I O modules To connect more than four I O modules use an additional power supply such as the EIG PSIO Connect multiple I O modules using the RS 485 side ports M Six feet of RS 485 cable harness is supplied The cable harness brings power to the display from the Nexus Meter which supplies 15 20V DC at 50 200mA See Chapter 5 for power supply and com munication details 1 125 2 85cm gt Mounting Bracket lt gt 2 x 625 1 58cm T 0 015 38mm Mounting Bracket Figure 3 7 Nexus I O Modules Mounting Diagram Overhead View Mounting Brackets MBIO Female RS 485 Side Port Male RS 485 Side Port Figure 3 8 Nexus LO Module Communication Ports
38. 1 1 3 Blondell s Theorem and Three Phase Measurement 2 2 1 4 1 2 Power Energy and Demand lt lt lt 1 6 1 3 Reactive Energy and Power Factor lt lt lt lt 1 8 1 4 Harmonic Distortion lt lt lt lt lt lt a 1 10 1 55 Power Quality ud a Seth th RE Zl Be ne ud er 1 13 Chapter 2 Nexus Overview 2 12 Th Nexus System s EE m ds des 08 eae Re e de an k aab iA 2 1 2 2 DNP V3 00 Level 1 and Level2 e 2 2 2 35 BUCKED 4 wag ake is oe A e aE 4 aie Le SR SU Ale e Le 2 2 2 4 INP2 Internal Modem with Dial In Dial Out Option lt 2 3 2 4 1 Hardware Overview lt lt 2 3 2 4 2 Dial In Function s lt a a a a 2 3 2 4 3 Dial Out Function lt lt lt a 2 3 2 5 Total Web Solutions lt lt lt lt 2 4 2 5 1 Hardware Overview 2 4 2 5 2 Hardware Connection a lt lt lt lt lt lt 2 4 2 6 Measurements and Calculations lt lt lt lt lt 2 6 2 7 Demand Integrators lt lt lt lt 2 10 2 8 Nexus External I O Modules Optional lt lt lt lt 2
39. 12 2 9 Nexus 1250 1252 Meter Specifications lt lt lt 2 13 2 10 Nexus P40N P41N P43N External Display Specifications 2 14 2 11 Nexus P60N Touch Screen Display Specifications lt lt lt 2 14 Chapter 3 Hardware Installation 3 1 Mounting the Nexus 1259 1252 Meter 3 1 3 2 Mounting the Nexus P40N DAIN P43N External Displays 3 3 3 3 Mounting the Nexus P60N Touch Screen External Display 3 4 3 4 Mounting the Nexus External I O Modules lt 3 6 Chapter 4 Electrical Installation 4 1 Wiring the Monitored Inputs and Voltages lt lt lt 4 1 4 2 Fusing the Voltage Connections lt lt lt lt lt 4 1 4 3 Wiring the Monitored Inputs VRef lt 4 1 4 4 Wiring the Monitored Inputs VAUX 4 1 4 5 Wiring the Monitored Inputs Currents lt lt lt lt 4 1 4 6 Isolating a CT Connection Reversal lt lt lt lt lt 4 2 4 7 Instrument Power Connections lt lt 4 2 4 8 Wiring Diagrams lt 4 3 G Electro Industries GaugeTech Doc E107706 V1 25 V
40. 28cm Figure 3 3 Nexus P40N LED External Display Mounting Diagrams G Electro Industries GaugeTech Doc E107706 V1 25 3 3 3 3 Mounting the Nexus P60N Touch Screen External Display Aperture is 12 14 9 10m 4 763 13503 Pixel Mats 320 x 240 is 115 8 6cm 4 40 crews Dn ju 7 36 18 60m t u up 032 3 76 85cm typ 2 12 IO Dom ID Zem typ 0 63cm typ 2 00 20 3cm typ 1 55 3 40m e Figure 3 4 Nexus P60N Touch Screen Display Mounting Diagram M The Nexus 1250 1252 P60N Touch Screen Display mounts easily using the diagrams above and on the next page A bezel and a gasket are included with the P60N Since the P6ON employs an LCD display the viewing angle must be considered when mounting Install the P60N at a height and angle that make it easy for the operator to see and access the screen E For optimum performance maintain the following conditions where the Touch Screen Display is mounted e Operating Temperature 0 C to 50 C 32 F to 122 F e Storage Temperature 20 C to 70 C 36 F to 158 F e Relative Humidity 25 to 65 non condensing G Electro Industries GaugeTech CONTRAST RS 232 O ne 1 Factory TXA 2 Sois Pen kl EI Test ne D A ji GND 5 SEWER Connector O DON 12 30VDC 5 GND 4 485 3 gt Connect to NEXUS Figure 3 5 Nexus P60N Back Detail Doc E107706 V1 25 3 4 0 180 4 57 1 620 40 5 380 156 7 7 0
41. 4416 550Y C t 0772272003 09 43 58 Ce Volts B 0 118 14396 360V Next PST EEE Ned PLT TEE Volts C 0 119 14359710 Status Flicker Monitoring Start Stop Reset This section describes the Main Screen functions The available values Instantaneous Short Term Long Term will be described below G Electro Industries GaugeTech Doc E107706 V1 25 12 4 Time Start Reset 1s the time when Flicker was started or reset A Reset of Flicker causes the Max Min values to be cleared and restarts the Flicker Pst and Plt timers A Start of Flicker is also equivalent to a Reset in that the PST and PLT are restarted and the Max Min Values are cleared Stop corresponds to the time when Flicker is turned off Current is the current clock time Next Pst is the countdown time to when the next Pst value is available Next Plt is the countdown time to when the next Plt value is available Status Indicates the current status Active On Stopped Off Frequency Base is the current operating frequency selected by the user 50 or 60 Hz Current is the real time frequency measurement of the applied voltage Base Voltage is the normalized voltage for the selected frequency 230 V for 50 Hz or 120 V for 60 Hz Flicker Monitoring Clicking on Stop causes Flicker to stop being processed and freezes all the current values Stop Time is recorded and clears the current Max Min Values Clicking on Start starts Flicker processing Start Time i
42. 7H Baud Rate 57600 Baud Transmit Delay Time 20 csec G Electro Industries GaugeTech Doc E107706 V1 25 9 15 9 9 3 Normal Mode The device is polling the inputs at 100Hz once every 10 msec debouncing the inputs and incrementing the Transition Accumulators for each channel as appropriate The inputs are represented by Channel 1 in the LSB through Channel 8 in the MSB of the low order byte of the register The Modbus Map for the Digital Status Input Modules and operating details can be found in the Modbus Communicating 1 0 Modules Manual 9 10 Specifications The following multiple analog or digital I O modules mount externally to the Nexus Socket Meter The Nexus 1262 and 1272 Units DO NOT SUPPORT I O MODULES Use an additional power supply such as PSIO to provide I O capability See Chapter 6 for mounting diagrams Analog Transducer Signal Outputs Up to two modules can be used with the Nexus 1mAON4 4 Analog Outputs scalable bidirectional 1mAON8 8 Analog Outputs scalable bidirectional 20mAON4 4 Analog Outputs scalable 20mAONS 8 Analog Outputs scalable Analog Transducer Inputs Multiple modules can be used 8AI1 8 Analog Inputs 0 1mA scalable and bidirectional 8AI2 8 Analog Inputs 0 20mA scalable and bidirectional 8AI3 8 Analog Inputs 0 5V dc scalable and bidirectional 8AI4 8 Analog Inputs 0 10V gc scalable and bidirectional Digital Dry Contact Relay Outputs Multiple modules can be used
43. 8 F e Storage Temperature 45 C to 85 C 49 F to 185 F e Relative Humidity 5 to 95 non condensing lt 10 5 26 67 cm gt 2 x 3 25 8 25cm lt 2x4 0 10 1 6cm gt 7 25 18 41cm 6 74 17 11cm 4 x 0 221 5 61mm Thru Slot SE For 10 Screw Figure 3 1 Nexus Meter Mounting Diagram Top View G Electro Industries GaugeTech Doc E107706 V1 25 3 1 Nexus Meter Mounting Diagram Side View lt lt 2 35 5 96cm gt lt 3 40 8 63cm MAX gt Figure 3 2 G Electro Industries GaugeTech Doc E107706 V1 25 3 2 3 2 Mounting the Nexus LED External Displays M The Nexus 1250 1252 LED Displays Model P40N P41N and P43N mount using a standard ANSI C39 1 drill plan M Secure the four mounting studs to the back of the panel with the supplied nuts IE Six feet of RS 485 communication power cable harness is supplied Allow for at least a 1 25 inch 3 17cm diameter hole in the back for the cable harness See Chapter 5 for communication and power supply details M The cable harness brings power to the display from the Nexus 1250 1252 Meter which supplies 15 20V DC The P40N or P41N or P43N can draw up to 500 mA in display test mode 4 38 Sq 11 12cm gt 75 SE 9 05mm 1 438 3 65cm Nexus P40N Display Front View Nexus P40N Display Side View 3 38 8 58cm Sa ANSI C39 1 Drill Plan 1 687 14
44. 91 2004 17 5616 17 MAX VOLTS B 2 238 06 21 2004 17 56 16 17 MAX VOLIS C 2 110 06 21 2004 17 56 16 17 MIN VOITS A 0023 05 03 2004 17 56 16 17 MIN VOLTS B 0 023 05 09 2004 17 56 16 17 MIN VOLTS C 0 023 05 03 2004 17 56 16 17 SIAIUS Stopped SHORTY LONG POLLING ISI TERM TERM MAIN NEXT TART STOP f RESE LIMIT STATUS 3 05 PM ITEM VAI UF STATUS SFTTING 15 Kdgz Volts AN 121 90 Y oul a 121 32 V IN 119 68 ta Rdga Walta AN 17188 our bk 171 37 119 68 13 Kdgz Vots UN 121 84 z 121 32 119 68 1aRdga 1 A 03061 5 1000 4 9000 1sRdgs 1 B 0 3061 gt 5 1000 d A sono In Rdgs1i C 0 3061 gt 5 1000 4 9000 ta Raga VA Tot 1980 Q 16700 je Rdge VAR Tot o 450 00 IN 376 00 gt gt DS SL POLLING NEXT MAIN NEXT po PHASOR ANALYSIS 1 16 05 3 52 PM 270 60 003 Hz VH 0 00 VB 119 45 VC 239 67 1A 349 44 A 1B 109 01 y 1C 228 89 ES va lactacin e VAB 329 75 jsa Ke Er VBC 68 93 90 VCA 209 04 O Poring x oso REAL TIME WAVEFORM GRAPH THD voura A Frequency on KFACTOR 122 60 60 003Hz VOLTS A MAIN NEXT CHANNEL POLLING G Electro Industries GaugeTech Doc t E107706 V1 25 6 14 E SPECTRUM Harmonic Spectrum Analysis HARMONIC SPECTRUM 1116 05 3 52 Pm Select a Channel by touching the CHANNEL ANALYSIS Ss koco vas na A 2 33 123 03 60 003Hz button Graphs and readings appear for the 100 7 selected channel DER Zoom In or Out for d
45. D 0 Digilal Inpul Snapshots 9 0 Digital Output Snapshots Q O Digilal Oulpul Snapshots 0 0 Flicker 1536 100 Waveform Triggers 26 Wavetorm Samples 26 PQ CBEMA 43 NEXT POLLING MAIN METER RESET COMMANDS MAX MIN AND DEMAND HOUR PT AND V T COUNTERS ALL LOGS TOU FOR CURRENT SEASON amp MONTH CONTRAST 37 BACKLIGHT OFF DELAY SEC 388 MAIN NEXT NEXUS LINK SETTINGS NEXUS ADDRESS UP 001 PROTOCOL MODBUS RTU BAUD 9600 UP POLLING MAIN NEXT G Electro Industries GaugeTech Doc E107706 V1 25 6 16 M NEXUS PORT SETTINGS Port 1 Baud and Protocol selected Port 2 Baud and Protocol selected PORT BAUD PROTOCOL Port 3 Baud and Protocol selected Port 4 Baud and Protocol selected NEXUS PORT SETTINGS 1 115200 MoDBUS RTU 2 57600 MooDBUS RTU 3 9600 MoDg8us RTU 57600 MooDBuUS RTU POLLING MAIN NEXT E NEXUS STATUS NEXUS STATUS Device Type Nexus 1252 AA Serial Number 10 digit number Nexus 1252 Comm State Healthy or Unhealthy SERIAL NUMBER COMM STATE oDD0000000 HEALTHY Nv Ram 4 MB Dese Se DSP State Healthy or Unhealthy HEALTHY HEALTHY Protection Password Enabled or Disabled PROTECTION ON TIME On Time Current Date and Time Paco crea a a K aera POLLING E FIRMWARE VERSIONS PRE VERSIONS Nexus 1252 Nexus 1252 Boot 601 BOOT 601 Run time 606 DSP Boot 600 DSP Run time 604 LOD
46. ER SUPPLY OPTION Electro Industries GaugeTech Doc E107706 V1 25 000 000 000 000 LINE CT_SHORTING SWITC x OR TEST BLOCK gt 7 s DEER el o SE UE m a RES NE pe ENERO MEE A d ol pc SWITCHGEAR CHASSIS l GROUND 0 25 A SUPPLY POWER INPUT L gt DEPENDENT ON EQUIPPED POWER SUPPLY OPTION N C B A LOAD Figure 4 8 4 Wire 3 Element Grounded Delta with 4 CTs G Option G Electro Industries GaugeTech Doc E107706 V1 25 G Electro Industries GaugeTech Doc E107706 V1 25 Chapter 5 Communication Wiring 5 1 Communication Overview IE RS 232 communication is used to connect a single Nexus 1250 1252 Meter with another device such as a computer RTU or PLC The link is viable for a distance up to 50 feet 15 2 m and is available only through the Nexus 1250 1252 Meter s Port 1 You must set the selector switch beneath the port to RS 232 see Figure 5 3 E RS 485 communication allows multiple Nexus Meters to communicate with another device at a local or remote site The I O modules and the Nexus Display use RS 485 to communicate with the Nexus Meter All RS 485 links are viable for a distance up to 4000 feet 1220 m Ports 1 through 4 on the Nexus 1250 1252 Meter are two wire RS 485 connections operating up to 115 200 baud To use Port 1 for RS 485 set the selector switch to RS 485 see Figure 5 3 RS 232 485 Converter Unicom 2500 Up to 31 Devices 4000 feet maximum without a
47. Electro Industries GaugeTech Doc E107706 V1 25 3 6 Nexus UO Modules Mounting Diagram Front View Mounting Bracket MBIO Mounting Bracket MBIO 1 25 3 17cm Y Per Module 2 20 5 58cm 2x1 10 2 79cm 3 41 8 66cm y gt p a Y n 1 235 3 13cm 0 605 1 53cm Figure 3 9 Electro Industries GaugeTech Doc E107706 V1 25 3 7 G Electro Industries GaugeTech Doc E107706 V1 25 Chapter 4 Electrical Installation 4 1 Wiring the Monitored Inputs and Voltages Select a wiring diagram from Section 4 8 that best suits your application Wire the Nexus 1250 1252 exactly as shown For proper operation the voltage connection must be maintained and must correspond to the correct terminal Program the CT and PT Ratios in the Device Profile section of the Communicator EXT software see the Communicator EXT User Manual for details The cable required to terminate the voltage sense circuit should have an insulation rating greater than 600V AC and a current rating greater than 0 1 Amp Use a minimum of 14 AWG wire for all phase voltage and current connections 4 2 Fusing the Voltage Connections For accuracy of the readings and for protection EIG requires using 0 25 Amp rated fuses on all voltage inputs as shown in the wiring diagrams see section 4 8 The Nexus Meter can handle a maximum voltage of 150V phase to neutral and 300V phase to phase Potential Transformers PTs are required for hig
48. Figure 1 7 and adjust the energy reading to an hourly value that constitutes the demand In the example the accumulated energy is 14 92 kWh But this measurement was made over a 15 minute interval To convert the reading to a demand value it must be normalized to a 60 minute interval If the pattern were repeated for an additional three 15 minute intervals the total energy would be four times the measured value or 59 68 kWh The same process is applied to calculate the 15 minute demand value The demand value associated with the example load is 59 68 kWh hr or 59 68 kWd Note that the peak instantaneous value of power is 80 kW significantly more than the demand value G Electro Industries GaugeTech Doc E107706 V1 25 1 7 E Figure 1 8 shows another example of energy and demand In this case each bar represents the energy consumed in a 15 minute interval The energy use in each interval typically falls between 50 and 70 kWh However during two intervals the energy rises sharply and peaks at 100 kWh in interval number 7 This peak of usage will result in setting a high demand reading For each interval shown the demand value would be four times the indicated energy reading So interval 1 would have an associated demand of 240 kWh hr Interval 7 will have a demand value of 400 kWh hr In the data shown this is the peak demand value and would be the number that would set the demand charge on the utility bill 100 80 60 40 2
49. H OK 1000H Problem Bit 1 1 EEPROM Failure Bit2 1 Checksum for Communications Settings bad Bit3 1 Checksum for Programmable Settings bad Bit4 1 1 or mor Communications Settings are invalid Bit5 1 1 or more Programmable Settings are invalid Bit6 1 1 or more Programmable Settings have been modified Bit 7 1 Forced Default by Reset Value Bit 15 1 Normal Operation of the device is disabled G Electro Industries GaugeTech Doc E107706 V1 25 9 14 9 9 Digital Status Input Module Digital Status Input Module Specifications Model Number 8DI1 RS 485 Modbus RTU Communication Programmable Baud Rates 4800 9600 19200 57600 15 20V ge at 50 200 mA Power Requirement Nexus 1250 1252 Unit supports up to 4 Modules 20 to 79 C 4 to 158 F 2 s Factory Settings ov en 9 9 1 Overview BE The Digital Status Input Module is used for either additional status detect or for accumulating pulses from external equipment such as power meters water meters etc M Nexus 1250 1252 Unit supplies power for up to 4 connected Digital Status Input modules See section 9 2 for power and communication details Refer to sections 5 12 5 13 to determine if you must use an additonal power source such as the EIG PSIO 9 9 2 Communication E Maximum registers per request read or write is 4 registers orm M The device will operate with the following Default Mode Parameters See section 9 4 1 for details Address 247 F
50. Host IP Address per your network administrator Example 10 0 0 1 Network Port 502 Protocol Modbus TCP 4 Click the Connect button at the bottom of the screen Communicator EXT connects to the Nexus with the Host IP Address via the Network Electro Industries GaugeTech Doc 107706 V1 25 2 5 2 6 Measurements and Calculations The Nexus 1250 1252 Meter measures many different power parameters The following is a list of the formulas used to conduct calculations with samples for Wye and Delta services Samples for Wye Van Ybr Ven la b le 1 Samples for Delta Vab Vbo Y n ca la p ic E Root Mean Square RMS of Phase to Neutral Voltages n number of samples For Wye x an bn cn E Root Mean Square RMS of Currents n number of samples For Wye x a b c n For Delta x a b c IE Root Mean Square RMS of Phase to Phase Voltages n number of samples For Wye x y an bn or bn en or en an n 2 gt War Y ya ms t 1 Nous n For Delta xy ab bc ca Electro Industries GaugeTech Doc E107706 V1 25 2 6 E Power Watts per phase For Wye x a b c n KE W IT W n E Apparent Power VA per phase For Wye x a b c VA V x RMS yy I RMS y BE Reactive Power VAR per phase For Wye x a b c VAR NVA Watt E Power Watts Total For Wye W W W W For Delta n ei v ei 2 Varo Au BCo Co E W n
51. ISTER DEMAND Month Current Season Current Month 01 16 05 00 00 00 10 04 05 23 59 59 BLOCK WINDOW B TOU Register Demand RECEIVED KWATT 57 40 0116 05 09 58 03 RECEIVED KVAR 0 00 00 00 00 00 00 00 DELIVERED KVAR 98 00 01 16 05 16 29 48 hd Block Fixed Window kWatth kVARhr DELIVERED KWATT 0 00 00 00 00 00 00 00 kWatth kVARh Coin kVARh COIN RECEIVED KVAR 78 67 COIN DELIVERED KVAR 0 00 Coin kVARh Touch ACCUM to view TOU Accumulations Pons CURRENT Touch Next Reg to scroll Registers 1 8 and Totals accum MONTH dove Touch Next Group to scroll Prior Season Prior Month Current Season Current Month FLICKER INSTANTANEOUS TIMF E FLICKER INSTANTANEOUS i sue Geer 01 16 05 15 52 16 Nol PST OOmin O0scc e Time Start Reset Stop Current Next PST PLT pasada ve SS Gegen Jee M ATU Stopped Volts A 0 000 122721 VW e Status Active or Stopped FREQUENCY eee oo Se ci e Frequency se E Vols Gm 122711V d 60017 H7 e Base Voltage BASE VOLTAGE 120 Volls e Frequency POLLING Touch SHORT TERM or LONG TERM to view a en a RESE other Flicker screens Sai pese START or STOP will appear depending on Status FLICKER SHORT TERM PST TIME E FLICKER SHORT TERM m a VOLTS A 00 00 0000 00 00 00 00 VOLTS B 0 000 00 00 0000 00 00 00 00 VOLIS C 00 00 0000 00 00 00 00 hd Volts A B C MAX VOLTS A 7593 06 20 2004 09 10 00 19 MAX VOLTS B 7 112 06 20 2004 09 10 00 19 hd Max Volts A B C MAX VOLIS C 5 905 04 29
52. Initially the user must set up several parameters to properly configure Flicker Using Communicator EXT from the Icon Menu select Edit Device Profile From the Device Profile select Flicker Settings The following screen will appear G Electro Industries GaugeTech Doc E107706 V1 25 Flicker Settings Short term test time PST Minutes Long term test time PLT b gt Minutes Frequency 12 3 e Select a Pst time range from 1 to 10 minutes The standard measurement period is nominally 10 minutes e Select a Plt time range from 1 to 240 minutes The standard measurement is nominally 12 Pst periods 120 minutes Plt time must always be equal to or great than and a multiple of Pst time This is reflected in the selections available to the user e Select the frequency of operation 50 Hz is the approved frequency according to Flicker standards A 60 Hz implementation is available and can be selected This implementation is the proposed 60 Hz standard that is still in the approval process Remember the voltage is normalized For 50 Hz the normalized voltage is 230 V and for 60 Hz the normalized voltage is 120 V Press OK when you are finished Press Help for more information on this topic 12 4 Software User Interface m Main screen From the Communicator EXT Icon Menu select Real Time Poll Flicker The following screen appears Instantaneous ShortTerm__ Long Term PINST Yoltage Reading Volts A 0 098 1
53. LA KA EA M LA LA WA WA vi ba Va ER EI WI E Ga Min Yolts C 00 02 2000 01 42 00 09 Base Voltage Flicker Monitoring Start Stop Reset y E Long Term Readings Click on the Long Term tab to access the Plt readings The screen below displays three groups of Plt values Plt Readings Displayed e Current Plt values for Va Vb and Vc and the time of computation e Current Plt Max values for Va Vb and Vc since the last reset and the time of the last reset e Current Plt Min values for Va Vb and Vc since the last reset and the time of the last reset G Electro Industries GaugeTech Doc E107706 V1 25 12 6 Flicker Instantaneous ShortTem Y PLT Time Volts A 0 3419 07 22 2003 09 58 00 11 Current A Volts B 8 07 22 2003 09 58 00 11 NextPST I Next PLT FE Volts C 3 07 22 2003 09 58 00 11 Status Max Volts A EE D 00 02 2000 01 47 00 17 Max Volts B 13 993 00 14 2000 04 33 00 09 Max Volts C 00 14 2000 02 00 00 07 Frequency gt Base eme Min Volts A 00 02 2000 01 42 00 09 Current SESE Min Volts B a 00 02 2000 01 42 00 09 Min Volts C E 00 02 2000 01 42 00 09 Base Yoltage Flicker Monitoring Start Stop Reset 12 5 Logging The Nexus is capable of logging Flicker values in an independent log When Flicker is on entries are made into the log in accordance with the times that associated values occur Pst Pst Max Pst Min Plt Plt Max Plt Min Sta
54. M Usually a wye connected service will have four wires three wires for the phases and one for the neutral The three phase wires connect to the three phases as shown in Figure 1 1 The neutral wire 1s typically tied to the ground or center point of the wye refer to Figure 1 1 In many industrial applications the facility will be fed with a four wire wye service but only three wires will be run to individual loads The load is then often referred to as a delta connected load but the service to the facility is still a wye service it contains four wires if you trace the circuit back to its source usually a transformer In this type of connection the phase to ground voltage will be the phase to ground voltage indicated in Table 1 even though a neutral or ground wire is not physically present at the load The transformer is the best place to determine the circuit connection type because this is a location where the voltage reference to ground can be conclusively identified G Electro Industries GaugeTech Doc E107706 V1 25 1 2 1 1 2 Delta Connection M Delta connected services may be fed with either three wires or four wires In a three phase delta service the load windings are connected from phase to phase rather than from phase to ground Figure 1 3 shows the physical load connections for a delta service Phase C PY Q Q A Phase A Phase B Figure 1 3 Three Phase Delta Winding Relationship In this example of a delta service thre
55. Modbus Communicating I O Modules Manual Each latching relay will hold its state in the event of a power loss Electro Industries GaugeTech Doc E107706 V1 25 9 11 9 7 2 Communication E Maximum registers per request read or write is 4 registers orm M The device will operate with the following Default Parameters Address 247 F7H Baud Rate 57600 Baud Transmit Delay Time 20 csec E Some situations will cause the device to operate with the above Default Parameters See section 9 4 1 for details of Default Mode 9 7 3 Normal Mode IE Normal Mode consists of one process 1 The device accepts new commands to control the relays G Electro Industries GaugeTech Doc E107706 V1 25 9 12 9 8 Digital Solid State Pulse Output KYZ Module Digital Solid State Pulse Output KYZ Module Specifications Model Number 4PO1 RS 485 Modbus RTU Communication Programmable Baud Rates 4800 9600 19200 57600 15 20V go at 50 200 mA Power Requirement Nexus 1250 1252 Unit supports up to 4 Modules Operating Temperature 20 to 79 C 4 to 158 F Voltage Rating Up to 300V e Commands Accepted Read and Write with at least 4 registers of data per command Memory 256 byte IC EEPROM for storage of Programmable Settings and Nonvolatile Memory Modbus Address 160 Factory Settings Baud Rate 57600 Transmit Delay Time 0 Modbus Address 247 Default Settings Reset Button Baud Rate 57600 Transmit Delay Time 20 csec 9 8 1
56. Mounting Bracket The left Mounting Bracket is the one with the PEM Fasten the internal screw tightly into the left Mounting Bracket 4 Next slide the female RS 485 port into the male RS 485 side port to connect the next I O module to the left module Fasten together enough to grab but do not tighten One by one combine the modules together using the Integrated Fastening System Fig 9 1 If you require an additional power supply attach a PSIO power supply to the right of each group of 4 UO Modules section 9 3 G Electro Industries GaugeTech Doc E107706 V1 25 9 5 NOTE The PB1 can also be used for a Low Voltage Power Supply It must be mounted separately 5 Once you have combined all the I O modules together for the group fasten tightly This final tightening will lock the whole group together as a unit 6 Attach the right Mounting Bracket to the right side of the group using small phillips head screws provided 7 Then mount the group of modules on a secure flat surface This procedure will ensure that all modules stay securely connected 9 4 Factory Settings and Reset Button E Factory Settings All Nexus I O Modules are shipped with a preset address and a baud rate of 57600 See below for addresses E Reset Button If there is a communication problem or if you are unsure of a module s address and baud rate press and hold the RESET button for 3 seconds the module will reset to a default address of 247 at 57600 ba
57. Nexus 1250 1252 HIGH PERFORMANCE SCADA MONITOR Installation amp Operation Manual Version 1 25 November 13 2006 Doc E107706 V1 25 Electro Industries Gauge Tech 1800 SHAMES DRIVE WESTBURY NEW YORK 11590 TEL 516 334 0870 Fax 516 338 4741 SALES ELECTROIND COM WWW ELECTROIND COM The Leader in Web Accessed Power Monitoring and Control G Electro Industries GaugeTech Doc E107706 V1 25 Nexus 1250 1252 Installation and Operation Manual Revision 1 25 Published by Electro Industries Gauge Tech 1800 Shames Drive Westbury NY 11590 All rights reserved No part of this publication may be reproduced or transmitted in any form or by any means electronic or mechanical including photocopying recording or information storage or retrieval systems or any future forms of duplication for any purpose other than the purchaser s use without the expressed written permission of Electro Industries GaugeTech 2006 Electro Industries GaugeTech Printed in the United States of America G Electro Industries GaugeTech Doc E107706 V1 25 Customer Service and Support Customer support is available 9 00 am to 4 30 pm eastern standard time Monday through Friday Please have the model serial number and a detailed problem description available If the problem concerns a particular reading please have all meter readings available When returning any merchandise to EIG a return materials authorization numbe
58. Phase Angle Vab bc ca Phase Sequence GG Electro Industries GaugeTech Doc E107706 V1 25 6 4 6 4 Navigational Map of Dynamic Readings Mode B Use LEFT RIGHT arrow keys to navigate Readings B Use UP DOWN arrows to scroll between groups Max THD Volts Min THD Volts Return to First 1 Second Volts Maximum Volts AN BN CN Minimum Volts AN BN CN THD Volts AN BN CN AN BN CN mOConbi 1 Second Volts AB BC CA 1 Second TA IB IC 1 Second kWatt kVAR 1 Second kVA PF lag Frequency Positive kWatthour Q1 Q4 Negative kWatthr 02 03 kItA Phase Angles V AN BN CN Maximum Volts AB BC CA Maximum TA IB IC Max kWatt kVAR CoIn kVAR Positive kVAhr QI Positive kVAhr Q2 Phase Angles I A B C Minimum IA IB IC Max kWatt kVAR CoIn kVAR Positive kVARhr Ql Positive kVARhr Q2 kItC Minimum Volts AB BC CA THD IA IB IC Block WinAvg Max kWatt kVAR CoIn kVAR Positive kVAhr Q4 Positive kVAhr Q3 2 kVtA Phase Angles V AB BC CA AN BN CN Return to First Reading Max THD TA IB IC Negative kVARhr 04 Negative kVARhr 03 2 kV tB Phase Seguence Min THD IA IB IC Pred Rol Win Avg kWatt kVAR Coln kVAR 2 kV tC AN BN CN Reading Return to First Reading 1 Second INc INm Return to First Reading Return to First Reading Return to First Reading Return to First Reading Retur
59. R MODULE ADDRESS VA RATING 1mAON4 0 1mA 4 Analog Outputs 128 2 7 VA ImAON3 0 1mA 8 Analog Outputs 128 3 2 VA 20mAON4 4 20mA 4 Analog Outputs 132 5 0 VA 20mAON8 4 20mA 8 Analog Outputs 132 8 5 VA 8All 0 1mA 8 Analog Outputs 136 2 3 VA 8A12 0 20mA 8 Analog Outputs 140 2 3 VA 8A13 0 5V DC 8 Analog Outputs 144 2 3 VA 8A14 0 10V DC 8 Analog Outputs 148 2 3 VA 4RO1 4 Latching Relay Outputs 156 2 7 VA 4PO1 4 KYZ Pulse Outputs 160 2 7 VA 8D11 8 Status Inputs Wet Dry 164 1 0 VA NEXUS DISPLAYS VA RATINGS P40N P41N or P43N Nexus LED Display 8 VA P60N Nexus Touch Screen Display 5 VA G Electro Industries GaugeTech Doc E107706 V1 25 5 15 5 14 Linking Multiple Nexus Devices in Series M You may connect a total of 31 Nexus 1250 1252 Meters in series on a single bus using RS 485 The cable length may not exceed 4000 feet 1219 meters Before assembling the bus each Nexus Meter must be assigned a unique address see the Communicator EXT User Manual M Connect the A and B terminals of each Nexus Meter Use jumpers on any RS 485 Master connected at the end of the chain see section 5 5 IE Connect the shield to the S terminal on each Nexus and to the Ground on the RS 485 Master This connection is used to reference the Nexus port to the same potential as the source It is not an earth ground connection You must also connect the shield to earth ground at one point M Provide resistors at each end connected to the and lines
60. RIGINAL COST OF THE PRODUCT SOLD Statement of Calibration Our instruments are inspected and tested in accordance with specifications published by Electro Industries GaugeTech The accuracy and a calibration of our instruments are traceable to the National Institute of Standards and Technology through equipment that is calibrated at planned intervals by comparison to certified standards Disclaimer The information presented in this publication has been carefully checked for reliability however no responsibility is assumed for inaccuracies The information contained in this document is subject to change without notice This symbol indicates that the operator must refer to an explanation in the operating instructions Please see Chapter 3 Hardware Installation for important safety information regarding installation and hookup of the Nexus 1250 1252 Meter G Electro Industries GaugeTech Doc E107706 V1 25 Il About Electro Industries GaugeTech Electro Industries Gauge Tech was founded in 1973 by Dr Samuel Kagan Dr Kagan s first innovation an affordable easy to use AC power meter revolutionized the power monitoring field In the 1980s Dr Kagan and his team at EIG developed a digital multifunction monitor capable of measuring every aspect of power EIG further transformed AC power metering and power distribution with the Futura device which supplies all the functionality of a fault recorder an event recorder and a data logger in
61. Reset Button Baud Rate 57600 Transmit Delay Time 20 csec 9 5 1 Overview The Analog Transducer Signal Output Modules 0 1mA or 4 20mA are available in either a 4 or 8 channel configuration Maximum registers per request read or write 1s 17 registers Nexus 1250 1252 Unit supplies power for up to two connected Analog Output modules See section 9 2 for power and communication details Refer to sections 5 12 5 13 to determine if you must use an additonal power source such as the EIG PSIO All outputs share a single common point This is also an isolated connection from ground Electro Industries GaugeTech Doc E107706 V1 25 9 7 M The Modbus Map for the Analog Output Module and operating details can be found in the Modbus Communicating I O Modules Manual 9 5 2 Normal Mode E Normal Mode is the same for the 0 1mA and the 4 20mA Analog Output Modules except for the number of processes performed by the modules Both devices 1 Accept new values through communication 2 Output current loops scaled from previously accepted values The 0 1mA module includes one more process in its Normal Mode 3 Read and average the A D and adjust values for Process 2 above BE The device will operate with the following default parameters Address 247 F7H Baud Rate 57600 Baud Transmit Delay Time 0 E Normal Operation is prevented by a number of occurrences See section 9 4 1 for details G Electro Industries GaugeTech Doc
62. S A Table of Logs for the Selected Channel are Volts AN shown here best teg Touch BACK to return to the Trending Analysis 1424 123 47 screen ee Touch PREVIOUS LOGS to view other logs 1415 12350 123 58 1412 123 63 123 51 14 09 123 50 123 48 POLLING PREVIOUS 20 160 LOGS LOGS G Electro Industries GaugeTech Doc t E107706 V1 25 6 15 E LOG STATUS Logging Statistics An Overview of the Logs for the Primary Meter The Number of Records and Memory Used are listed for each log RESET Meter Reset Commande WARNING RESETS cause data to be lost Touch the window for the Reset you want to perform Don t Reset changes to Reset Touch RESET NOW button OK will appear Touch OK to refresh screen go back to original screen e Max Min and Demand e Hour PT and V T Counters e All Logs e TOU for Current Session and Month SETTINGS LCD SCREEN SETTINGS Contrast Touch Up Down buttons to increase decrease settings Number 37 is optimum setting Backlight Off Delay number of seconds after use that backlight turns off Touch Up Down buttons to increase decrease settings E NEXUS LINK SETTING Nexus Address 000 255 Touch Up Down buttons to increase decrease settings Protocol selected Baud selected LOGGING STATISTICS 1 16 05 3 56 PM LOGS RECORDS MEMORY USED I fislorical Log1 8704 100 Histoncal Log2 3200 100 Limit Triggers 512 100 Limit Snapshots 512 100 Digital Input
63. V1 25 5 20 5 17 Remote Communication RS 232 EIG recommends using RS 485 wiring with a Modem Manager See section 5 13 For RS 232 communication use Port 1 Set the selector switch under the port to RS 232 Fig 5 3 Use an RS 232 serial extension cable connected to the 9 pin female serial port of the Nexus 1250 1252 Meter s Port 1 Program this port for Modbus ASCII See the Communicator EXT User Manual for details The link using RS 232 is capable for up to 50 feet 1219 meters You must use a Null Modem or Null Cable between the Nexus Meter and the remote modem when using RS 232 A Null Modem enables two DCE devices to communicate The figure below details how a null modem reconfigures the RS 232 pins Note Connecting the Nexus Meter to a modem via RS 485 protocol with EIG s Modem Manager converter eliminates the need for a Null Modem see section 5 13 The remote modem must be programmed for auto answer and set at a fixed baud rate of 9600 with no Flow Control See section 5 19 and the Communicator EXT User Manual for further details Pins at Null Modem Male End 1 2 3 4 5 6 7 8 20 1 2 3 8 20 7 4 5 6 Pins at Null Modem Female End Figure 5 19 Standard Null Modem Configuration 5 18 Remote Communication RS 485 Use any Port on the Nexus 1250 1252 If you use Port 1 set the selector switch beneath the port to RS 485 see Figure 5 3 The link using RS 485 is viable for up to 4000 feet 1219 meters Use Communic
64. a call to a specified location to make a report or perform some other function For log full conditions the meter will automatically download the log s that are nearing the full state Electro Industries GaugeTech Doc E107706 V1 25 2 3 2 5 Total Web Solutions M The 10 100BaseT Ethernet Option INP 100 is a fully customizable web server that uses XML to provide access to real time data via Internet Explorer EIG s name for this dynamic system is Total Web Solutions The system incorporates a highly programmable network card with built in memory that is installed in the 100BaseT Option meters Each card can be programmed to perform an extensive array of monitoring functions and the system is much faster than the 10BaseT Ethernet Option NOTE Nexus meters with the INP10 Option do not support Total Web Solutions 2 5 1 Hardware Overview BE The Nexus 1250 1252 with the 10 100BaseT Ethernet Option INP 100 has all the components of the standard Nexus 1250 1252 PLUS the capability of connection to a network through an Ethernet LAN or through the Internet via Modbus TCP HTTP SMTP FTP and or DHCP M The Internal Network Option of the Nexus Meter is an extremely versatile communication tool Adheres to IEEE 802 3 Ethernet standard using TCP IP Utilizes simple and inexpensive 100BaseT wiring and connections Plugs right into your network using built in RJ 45 jack Programmable to any IP address subnet mask and gateway requireme
65. address subnet mask and gateway requirements Communicates using the industry standard Modbus TCP protocol E With the Internal Network Option the standard Port 2 on the Nexus 1250 1252 becomes a gateway to allow additional Nexus Meters access via the LAN Simply connect a daisy chain of Nexus Meters together via RS 485 each with its own device address and using the same baud rates With this option you can access any of those instruments via the single LAN connection B The Internal Network Option allows multiple simultaneous connections via LAN to the Nexus You can access the Nexus with SCADA MV90 and RTU all at the same time E The Internal Network Option allows multiple users running Communicator EXT software to access the meter concurrently G Electro Industries GaugeTech Doc E107706 V1 25 11 2 11 2 Hardware Connection Use Standard RJ 45 10 100BaseT cable to connect with the Nexus 1250 1252 The RJ 45 line is inserted into the RJ 45 Port on the face of the Nexus with Internal Network Option Set the IP Address using the following steps Refer to Section 3 5 of the Communicator EXT User Manual for more details 1 From the Device Profile screen double click on the Communications Ports line then double click on any of the ports The Device Profile Communications Settings screen appears 2 In the Network Settings section enter data provided by your systems manager IP Address 10 0 0 1 Example Subnet Ma
66. at receive power from another source ie a computer or to devices that do not require power to operate S Shield The Shield connection is used to reference the Nexus port to the same potential as the source It is not an earth ground connection You must also connect the shield to earth ground at one point Do not connect the shield to ground at multiple points it will interfere with communication A B Two wire RS 485 communication terminals Connect the A terminal of the Nexus Port to the terminal of the device Connect the B terminal of the Nexus Port to the terminal of the device Electro Industries GaugeTech Doc E107706 V1 25 5 5 RS 485 communication allows multiple devices to communicate on a bus The Nexus 1250 1252 Ports 1 to 4 are RS 485 terminals viable for a distance of up to 4000 feet 1219 m Nexus Port 1 can be switched between RS 232 and RS 485 Below is a detail of a 2 wire RS 485 port 2 Wire RS 485 Port Twisted Shield Pair Connect to of next device Connect to of next device Figure 5 6 2 Wire RS 485 Port Detail For All RS 485 Connections Use a shielded twisted pair cable 22 AWG 0 33 mm or larger grounding the shield at one end only Establish point to point configurations for each device on a RS 485 bus Connect terminals to terminals connect terminals to terminals Protect cables from sources of electrical noise Avoid
67. ator EXT software to set the port s baud rate to 9600 and enable Modbus ASCII protocol See the Communicator EXT User Manual You must use an RS 485 to RS 232 converter and a NULL Modem EIG recommends using its Modem Manager a sophisticated RS 232 RS 485 converter that enables devices with different baud rates to communicate It also eliminates the need for a NULL modem see section 5 12 and automatically programs the modem to the proper configuration Also if the telephone lines are poor Modem Manager acts as a line buffer making the communication more reliable G Electro Industries GaugeTech Doc E107706 V1 25 5 21 5 19 Programming Modems for Remote Communication When a modem speaks to most RS 485 or RS 232 based devices it must be programmed for the communication to work This task is often quite complicated because modems are quirky when talking to remote devices If you are not using a Modem Manager device you must set the following strings to communicate with the remote Nexus Meter s Consult your modem s manual for the proper string settings or see section 5 15 for a list of selected modem strings M Modem Connected to a Computer the Originate Modem Restore modem to factory settings This erases all previously programmed settings Set modem to display Result Codes The computer will use the result codes Set modem to Verbal Result Codes The computer will use the verbal result codes Set modem to use DTR Signal This is
68. atts values into Nexus meter using Communicator software G Electro Industries GaugeTech Doc E107706 V1 25 7 8 Chapter 8 Nexus Time of Use 8 1 Introduction A Time of Use TOU usage structure takes into account the quantity of energy used and the time at which it was consumed The Nexus 1250 1252 TOU function available with the Communicator EXT software is designed to accommodate a variety of programmable rate structures Nexus TOU accumulates data based on the time scheme programmed into the Nexus Monitor See the Communicator EXT User Manual for details on programming the Nexus 1250 1252 20 Year TOU calendar and retrieving TOU data 8 2 The Nexus TOU Calendar G A Nexus TOU calendar sets the parameters for TOU data accumulation You may store up to twenty calendars in the Nexus 1250 1252 Monitor and an unlimited amount of calendar files on your computer The Nexus TOU calendar profile allows you to assign a programmable usage schedule eg Weekday Weekend Holiday to each day of the calendar year You may create up to 16 different TOU schedules Each TOU schedule divides the 24 hour day into fifteen minute intervals from 00 00 00 to 23 59 59 You may apply one of eight different programmable registers eg Peak Off Peak Shoulder Peak to each fifteen minute interval The Nexus 1250 1252 Monitor stores e accumulations on a seasonal basis up to four seasons per year e accumulati
69. ature components G Electro Industries GaugeTech Doc E107706 V1 25 1 8 Angle 6 Figure 1 9 Voltage and Complex M The voltage V and the total current I can be combined to calculate the apparent power or VA The voltage and the in phase current IR are combined to produce the real power or watts The volt age and the quadrature current IX are combined to calculate the reactive power The quadrature current may be lagging the voltage as shown in Figure 1 9 or it may lead the voltage When the quadrature current lags the voltage the load is requiring both real power watts and reactive power VARs When the quadrature current leads the voltage the load is requiring real power watts but is delivering reactive power VARs back into the system that is VARs are flowing in the opposite direction of the real power flow M Reactive power VARs is required in all power systems Any equipment that uses magnetization to operate requires VARs Usually the magnitude of VARs is relatively low compared to the real power quantities Utilities have an interest in maintaining VAR requirements at the customer to a low value in order to maximize the return on plant invested to deliver energy When lines are carrying VARS they cannot carry as many watts So keeping the VAR content low allows a line to carry its full capacity of watts In order to encourage customers to keep VAR requirements low most utilities impose a penalty if the VAR conte
70. ays into Port 3 or 4 on the Nexus Meter using the cable supplied The Displays operate at 9600 baud Port 3 is factory set to 9600 baud see Chapter 5 for communication details To use the Displays on another port configure that port to operate at 9600 baud using the Communicator EXT Software see the Communicator EXT User Manual 6 2 Nexus P40N P41N and P43N LED External Displays The Nexus P40N LED External Display can be used alone or it can serve as the Master for this grouping of displays The P40N prepares the data for the Slave displays the P41N and the P43N Once a second it sends a request to the Nexus meter All necessary data for the Slave displays is returned to the Master display upon this request and the Master sends the data to the Slaves in the proper format The Nexus P41N and P43N Slave displays listen to the Master and display and update values on the screen when they receive proper data These displays have no keypads Data can only be received 1t cannot be changed If there is no data for more than 5 seconds Communication Lost will appear on the bottom of the screen The following data is displayed when received e Amp Display P41N Amp A Amp B Amp C e Power Display P43N Watt VAR PF G Electro Industries 101 An LED Display LU IDN IL UU mn NN IL UO Van bn cn Up Down Arrows Left Right Arrows Mode Button Figure 6 1 Nexus P40N LED External Display G Electro Industries GaugeTech Doc
71. both star and tee connections see Figure 5 7 No more than two cables should be connected at any one point on an RS 485 network whether the connections are for devices converters or terminal strips Include all segments when calculating the total cable length of a network If you are not using an RS 485 repeater the maximum length for cable connecting all devices is 4000 feet 1219 meters RT EXPLANATION Termination Resistors are generally used on both ends of longer length transmission lines The value of the Termination Resistors is determined by the electrical parameters of the cable Use RTs only on Master and Last Slave when connecting multiple meters in a Daisy Chain Electro Industries GaugeTech Doc E107706 V1 25 5 6 Incorrect Connection T Tee Connection Incorrect The three wires connected in a T shape on both the and terminals will cause interfer ence problems RS 485 Port Incorrect Connection Star Star Connection Incorrect The three wires connected in a Star shape on both the and terminals will cause interference problems Figure 5 7 Incorrect T and Star Topologies G Electro Industries GaugeTech Doc E107706 V1 25 5 7 5 4 RS 485 Connection Nexus Meter to a Computer or PLC Use any Port on the Nexus 1250 1252 If you use Port 1 set the selector switch beneath the port to RS 485 see Figure 5 3 The link usin
72. bus Commands Time Synchronization The meter uses Serial Modbus Based Commands to change the date and time of the clock The meter relies upon the Internal Crystal between synchronization intervals This mode is used in conjunction with MV90 4 DNP Line Synchronization The meter uses DNP Protocol Commands to change the date and time of the clock The meter relies upon the Internal Crystal between synchronization intervals 5 IRIG B The meter uses a Signal Generating Device connected to the GPS Satellite System to synchronize Nexus Time This mode is accurate to within one millisecond This mode is detailed in section 5 23 G Electro Industries GaugeTech Doc E107706 V1 25 5 24 5 23 IRIG B Connections M IRIG B is a standard time code format that synchronizes event timestamping to within 1 millisecond An IRIG B signal generating device connected to the GPS satellite system will synchronize Nexus 1250 1252 Meters located at different geographic locations Nexus utilizes an UNMODULATED signal from a satelite controlled clock such as Arbiter 1093B For details on installation refer to the User s Manual for the satellite controlled clock in use Below are installation steps and tips that will help you M Connect the terminal of the Nexus Meter to the terminal of the signal generating device connect the terminal of the Nexus Meter to the terminal of the signal generating device Nexus IRIG B Port 7 IRIG B Time S
73. by performing the numerical calculations using factors derived by clicking the TLC Calculator button on the Transformer Loss screen of the Device Profile or by manually figuring values in section 7 2 1 Calculating Transformer Loss Compensation Percentages Work Sheet Enter the derived values in the Device Profile screen of the Nexus Communicator software values will automatically be entered from the TLC Calculator button M The Nexus Communicator software allows you to enable Transformer Loss Compensation for Losses due to Copper and Iron individually or simultaneously Losses can either be added to or subtracted from measured readings M Loss compensation values must be calculated based on the meter installation As a result transformer loss values must be normalized to the meter by converting the base voltage and current and taking into account the number of elements used in the metering installation For three element meters the installation must be normalized to the phase to neutral voltage and the phase current in two element meters the installation must be normalized to the phase to phase voltage and the phase current This process is described in the following sections G Electro Industries GaugeTech Doc E107706 V1 25 7 3 7 2 1 Loss Compensation in Three Element Installations M Loss compensation is based on the loss and impedance values provided on the transformer manufacturer s test report A typical test report will include a
74. concurrently with the Communicator EXT software see the Communicator EXT User Manual Thermal Demand Traditional analog watt hour Wh meters use heat sensitive elements to measure temperature rises produced by an increase in current flowing through the meter A pointer moves in proportion to the temperature change providing a record of demand The pointer remains at peak level until a subsequent increase in demand moves it again or until it is manually reset The Nexus 1250 1252 mimics traditional meters to provide Thermal Demand readings Each second as a new power level is computed a recurrence relation formula is applied This formula recomputes the thermal demand by averaging a small portion of the new power value with a large portion of the previous thermal demand value The proportioning of new to previous is programmable set by an averaging interval The averaging interval represents a 90 change in thermal demand to a step change in power Block Fixed Window Demand This convention records the average arithmetic mean demand for consecutive time intervals usually 15 minutes Example A typical setting of 15 minutes produces an average value every 15 minutes at 12 00 12 15 12 30 etc for power reading over the previous fifteen minute interval 11 45 12 00 12 00 12 15 12 15 12 30 etc Rolling Sliding Window Demand Rolling Window Demand functions like multiple overlapping Block Window Demands The programmable setti
75. der kWatt kVAR Maximum kWatt kVAR Coln kVAR Maximum kWatt kVAR Coln KVAR Block Fixed Window Average Maximum kWatt kVAR Coln kVAR Predictive Rolling Sliding Window Maximum kWatt kVAR Coln KVAR Group 5 VA PF Frequency Use the LEFT RIGHT arrows to access the following readings in order e KVA PF lag Hz e Maximum kVA Hz e Minimum kVA Hz Electro Industries GaugeTech Doc E107706 V1 25 6 3 Maximum Quadrant 1 Total PF Minimum Quadrant 1 Total PF Maximum Quadrant 2 Total PF Minimum Quadrant 2 Total PF Maximum Quadrant 3 Total PF Minimum Quadrant 3 Total PF Maximum Quadrant 4 Total PF Minimum Quadrant 4 Total PF E Group 6 Delivered Energy Use the LEFT RIGHT arrows to access the following readings in order kWatthr Quadrant 1 Quadrant 4 Primary kVAhr Quadrant 1 Primary kVARhr Quadrant 1 Primary kVAhr Quadrant 4 Primary kVARhr Quadrant 4 Primary E Group 7 Received Energy Use the LEFT RIGHT arrows to access the following readings in order kWatthr Quadrant 2 Quadrant 3 Primary kVAhr Quadrant 2 Primary kVARhr Quadrant 2 Primary kVAhr Quadrant 3 Primary kVARhr Quadrant 3 Primary E Group 8 Accumulations Use the LEFT RIGHT arrows to access the following readings in order e kItA e kItB e kItC e kVtA e kVtB e kVtC E Group 9 Phase Angles Use the LEFT RIGHT arrows to access the following readings in order Phase Angle Van bn cn Phase Angle la b c
76. dules to any enclosure Electro Industries GaugeTech Doc E107706 V1 25 2 12 2 9 Nexus 1250 1252 Meter Specifications Specification Control Power Requirements Input Voltage Range Input Current Range Input Withstanding Capabilities Burden VO Isolation Sensing Method Update Time Freguency Range Dimensions HxWxL Maximum Power Consumption Nominal Power Consumption Operating Temperature Auxiliary Output Power Voltage Maximum Auxiliary Power Current UL Listing Flicker 1252 Electro Industries GaugeTech Doc E107706 V1 25 Nexus Meter Option D 24V DC 20 48V DC 20 Option D2 120V AC DC 20 230V AC 20 150 Volts Phase to Neutral Standard for use with PTs 300 Volts Phase to Neutral Option G 10A Maximum Programmable to any CT Ratio Current Continuous 200 Rated Current Surge 10x maximum input for 3 seconds Surge Withstanding Per IEEE C37 90 1 Voltage 0 05VA 120V rms Current 0 002VA SA rms 2500V DC 60 Hz RMS 90 msec Fundamental 20 65 Hz Up to 83rd Harmonic Measuring Capability 3 4 x 7 3 x 10 5 inches 8 6 x 18 5 x 26 6 centimeters 40 watts with optional modules and display Approximately 12 watts without optional modules and display 40 C to 80 C 40 F to 176 F 15 20 V DC at 50 200mA 1 6A short protected 1244 Not evaluated for accuracy reliability or capability to perform intended function Evaluation per IEC 61000 4 15 2 13 2 10 N
77. e 9 16 Chapter 10 Nexus Monitor with INP2 Internal Modem Option 10 1 Hardware Overview m 10 1 10 2 Hardware Connection lt irat e 10 2 10 3 Dial In Function 2 2 a 10 2 10 4 Dial Out Function 10 2 Chapter 11 Nexus Monitor with Internal Network Option 11 1 Hardware Overview 11 1 11 2 Hardware Connection 2 2 11 3 Chapter 12 Flicker IDA OVERVIEW aoyo p do A B s yb e dy dE 12 1 12 2 Theory of Operation s e 12 1 A fs oh hot O se a ee ae hd De nd dy ets 12 3 12 4 Software User Interface lt lt 12 4 12 5 egene 2 a dde 3 de hong EN Bol Lin mt de e A ai 12 7 12 6 Polins sous rl vin sn thin bela nette do ud boa E usb amp 12 7 G Electro Industries GaugeTech Doc E107706 V1 25 vii 127 Eog VIEWER je ios e wah ote he as de Vos son ut leie lol gagh hud ph aa de 12 7 12 8 Performance Notes 2 a a a a a 12 8 Appendix A Transformer Loss Compensation Excel Spreadsheet with Examples Awl Calculating Values 4 s sz ee ce a eS Qk ge te de ei te Da n ek A 1 A 2 Excel Spreadsheet with Example Numbers A 1 Glossary of Terms G Electro Industries GaugeTech Doc 8 E107706 V1 25 VI Chapter 1 Three Phase Power Measurement This introduction to three phase power and p
78. e or current waveform for viewing and harmonic analysis Typically a waveform capture will be one or two cycles in duration and can be viewed as the actual waveform as a spectral view of the harmonic content or a tabular view showing the magnitude and phase shift of each harmonic value Data collected with waveform capture is typically not saved to memory Waveform capture is a real time data collection event Waveform capture should not be confused with waveform recording that is used to record multiple cycles of all voltage and current waveforms in response to a transient condition G Electro Industries GaugeTech Doc E107706 V1 25 1 12 1 5 Power Quality M Power quality can mean several different things The terms power quality and power quality problem have been applied to all types of conditions A simple definition of power quality problem is any voltage current or frequency deviation that results in mis operation or failure of customer equipment or systems The causes of power quality problems vary widely and may originate in the customer equipment in an adjacent customer facility or with the utility In his book Power Quality Primer Barry Kennedy provided information on different types of power quality problems Some of that information is summarized in Table 1 3 below Lightning Transient voltage disturbance Electrostatic discharge sub cycle duration Load switching Capacitor switching Impulse Transient Line cable sw
79. e wires will transmit the power to the load In a true delta service the phase to ground voltage will usually not be balanced because the ground is not at the center of the delta Figure 1 4 shows the phasor relationships between voltage and current on a three phase delta circuit In many delta services one corner of the delta is grounded This means the phase to ground voltage will be zero for one phase and will be full phase to phase voltage for the other two phases This is done for protective purposes Vbc Figure 1 4 Phasor Diagram Three Phase Voltages and Currents Delta Connected IE Another common delta connection is the four wire grounded delta used for lighting loads In this connection the center point of one winding is grounded On a 120 240 volt four wire grounded delta service the phase to ground voltage would be 120 volts on two phases and 208 volts on the third phase Figure 1 5 shows the phasor diagram for the voltages in a three phase four wire delta system G Electro Industries GaugeTech Doc E107706 V1 25 1 3 Vca 120 V 120 V 208 V Vab Fig 1 5 Phasor Diagram Showing Three phase Four wire Delta Connected System 1 1 3 Blondell s Theorem and Three Phase Measurement In 1893 an engineer and mathematician named Andre E Blondell set forth the first scientific basis for poly phase metering His theorem states If energy is supplied to any system of conductors through N wires the total power in t
80. e with Time Commands enable the Nexus meter to have internal time driven Frozen and Frozen Event data When the Nexus meter receives the Time and Interval the data will be created For complete details download the appropriate DNP User Manual from our website www electroind com 2 3 Flicker Nexus 1252 provides Flicker Evaluation in Instantaneous Short Term and Long Term Forms For a detailed explanation of Flicker see Chapter 12 of this manual Electro Industries GaugeTech Doc E107706 V1 25 2 2 2 4 INP2 Internal Modem with Dial In Dial Out Option 2 4 1 Hardware Overview E The INP2 Option for the Nexus 1250 1252 meter provides a direct connection to a standard tele phone line No additional hardware is required to establish a communication connection between the meter and a remote computer The RJ 11 Jack is on the face of the meter A standard telephone RJ 11 plug can connect the meter to a standard PSTN Public Switched Telephone Network E The modem operates at up to 56k baud The modem supports both incoming calls from a remote computer and automatic dial out calls when a defined event must be automatically reported With the device configured with the INP2 Option the meter has dial in capability and provides remote access to other Modbus based serial devices via the meter s RS 485 Gateway over your phone line The meter will recognize and respond to a Modbus Address of 1 With any other address the command will pass
81. each over a period of 2 hours The following formula is used N SP i l N Where Poy i 1 2 3 are consecutive readings of the short term severity Pot sti E Summary Flicker Changes in the illumination of light sources due to cyclical voltage variations Pinst Instantaneous flicker values in Perceptibility Units PU Pst Value based on 10 minute analysis Plt Value based on 12 Pst values Electro Industries GaugeTech Doc E107706 V1 25 12 2 Measurement Procedure 1 Original Signal with amplitude variations 2 Square demodulator 3 Weighted filter 4 Low pass filter 1 order 5 Statistical computing E Data available Pst Pst Max Pst Min values for long term recording Plt Plt Max Plt Min values for long term recording Block 1 Voltage Detector and Gain Control Input Voltage Adaptor Simulation Of Eye Brain Response Block 2 Block 3 High Pass Filter DC Square Removal Weighting een Filter Demodulator Low Pass Filter Carrier Removal Block 4 1st Squaring Order Multiplier Sliding Mean Filter Block 5 AD Converter Minimum Output Sampling 64 level Has Rate Classifier gt 50Hz Programming of short and long observation periods 12 3 Setup Output Recording Instantaneous Flicker in Perceptibility Units Figure 12 1 Simulation of Eye Brain Response Output and Data Display Pst Max Min Pst Pit Max Min Pit
82. ech Doc E107706 V1 25 7 5 E Meter Installation Data Instrument Transformers Numerator Denominator Multiplier Power Multiplier PT Multiplier times CT Multiplier MEA Enter the Numerator and Denominator for each instrument transformer For example a PT with a ratio of 7200 120 has a numerator or 7200 a denominator or 120 and a multiplier of 60 7200 120 60 1 Meter Secondary Voltage volts Meter Secondary Current amps For Transformer Voltage enter the Phase to Neutral value of Test Voltage previously calculated For Transformer Current enter the Full Load Current previously calculated For Multipliers enter the PT and CT multipliers previously calculated TrfIT Secondary is the Base Value of Voltage and Current at the Instrument Transformer Secondary of the Power Transformer These numbers are obtained by dividing the Transformer Voltage and Current by their respective Multipliers The Meter Trf values for Voltage and Current are obtained by dividing the Meter Base values by the TrfIT Secondary values E Load Loss at Transformer No Load Loss Watts KW 1 Phase kW No Load Loss No Load Loss VA kVA Exciting Current 1 Phase kVA Self Cooled Rating 100 EL 100 KVA No Load Loss VAR KVAR SQRT No Load Loss kVA No Load Loss KW SQRT y SORT W y SQRT G Electro Industries GaugeTech Doc E107706 V1 25 7 6 Full Load Loss Watts KW 1 Phase Kw Load Loss
83. ed N gt 0 330 17 503 e Maximum Current Calculated N Meas H 0 330 4 773 Calc N 0 968 23 129 Measured N Touch A B C to view Currents Detail G Electro Industries GaugeTech Doc t E107706 V1 25 6 11 AMPS Current Readings A B C e Real Time Current A B C Touch BACK to view the Amps main screen REAL TIME POWER Real Time Power Readings Details e Instant Watt VAR VA PF e Average Watt VAR VA PF e Predicted Watt VAR VA Touch the DEMAND button to go to the Demand Power screen shown below DEMAND POWER Demand Power Readings Details e Thermal Window Average Maximum kWatt kVAR Coln k VAR e Block Fixed Window Average Maximum kWatt kVAR Coln k VAR e Predictive Rolling Sliding Window Maximum kWatt kVAR Coln k VAR Touch R T button to view Real Time Power screen ENERGY Accumulated Energy Information Watthr Quadrant 2 Quadrant 3 Primary VAhr Quadrant 2 Primary VARhr Quadrant 2 Primary VAhr Quadrant 3 Primary VARhr Quadrant 3 Primary Watthr Quadrant 1 Quadrant 4 Primary VAhr for all Quadrants Primary Touch TOU button to view TOU Register Accumulations screen Electro Industries GaugeTech Doc E107706 V1 25 REAL TIME CURRENTS READINGS DETAILS AMPS A 0 280 B 14 974 C 0 293 BACK NEXT REAL TIME POWER READINGS DETAILS INSTANT AVERAGE PREDICTED 9079 14731 11635 WATTS VARS VA 11732 PF 0 536 LEAD 9290 9290 14658 11732 0 536
84. er the programmed Kg value Any of the natural numbers the negatives of those numbers or zero An optional modem within the meter e enclosure that connects to the RJ 11 telephone connector In the Nexus Modbus Map there are gaps between Registers For example the next Register after 08320 is 34817 Any unmapped Register stores no information and is said to be invalid An updated version of the CBEMA Curve that reflects further study into the performance of microprocessor devices The curve consists of a series of steps but still defines combinations of voltage magnitude and duration that will cause malfunction or damage kWh per pulse i e the energy kilowatt hours KW x demand interval in hours Output where the rate of changes between 1 and 0 reflects the magnitude of a metered quantity Liquid Crystal Display Light Emitting Diode In Modbus communication a Master Device initiates and controls all information transfer in the form of a Request Packet to a Slave Device The Slave reponds to each request The largest demand calculated during any interval over a billing period Glossar y 3 Modbus ASCII Modbus RTU Network NVRAM Optical Port Packet Percent THD Protocol PT Ratio Pulse Quadrant Programmable Values and Factors on the Nexus Electro Industries Gauge Tech Doc E107706 V1 25 Alternate version of the Modbus protocol that utilizes a different data transfer
85. ernal Display Serial Number Nexus Monitor G Electro Industries GaugeTech Doc E107706 V1 25 6 6 6 6 Navigational Map of Nexus Information Mode BE Use UP DOWN arrows to scroll between groups BE Use LEFT RIGHT arrows to scroll between readings Meter Time nco Comm Comm Comm Comm Return Settings Settings Settings Settings To Port 1 Port 2 Port 3 Port 4 First Reading Return To First Reading Display Primary Secondary Return To First Reading Run time Boot Serial Display Display Display Serial DSP Comm DSP Comm Monitor Electro Industries GaugeTech Doc tE107706 V1 25 6 7 Display Features Mode Use the MODE button to access the Display Features Mode from other Modes Use the UP DOWN arrows to navigate from Group to Group within this Mode See section 6 8 for a navigational map of the Display Features mode Group 1 Reset Max Min e Note If the password protection feature has been enabled with the Communicator EXT software you will need to enter a password to reset the max min readings To do this first press the Enter button Then enter the password one character at a time by pressing on the UP or DOWN arrows Each password character begins as an A Press the UP arrow to increment the character from A Z and then from 0 9 Press the DOWN arrow to decrement the character from A to 9 0 and then from Z A Press SET to enter each character the password When the e
86. es have ports through which they interface with other devices The port configurations are variations of the four types shown below Four Analog Outputs Eight Analog Outputs 0 1mA and 4 20mA 0 1mA and 4 20mA 0 1mA Analog Output Module 4 20mA Analog Output Module O com COM OUT 1 OUT 2 O o o OUT 3 o OUT 4 OUT 5 OUT 6 OUT 7 000000000 OUT 8 Eight Analog Inputs Four Relay Outputs 0 1mA 0 20mA or Four KYZ Pulse Outputs 0 5V ae 0 10V qe or Eight Status Inputs 0 1mA Analog Input Module ACD ICO NA o o o o o o o o o o o o o G Electra Industries GaugeTech Doc E107706 V1 25 9 2 Installing Nexus External UO Modules E VO modules must use the Nexus 1250 1252 Meter s Port 3 or 4 Six feet of RS 485 cable harness is supplied Attach one end of the cable to the port connectors may not be supplied insert the other end into the communication pins of the modules Male RS 485 Side Port Follow steps below and see Figure 9 2 below See section 9 3 for details on using multiple O modules LED s S Male Side Port on Nexus I O SL Module RT External SE ES Power Nexus 1250 1252 Port 3 or 4 gt A HB S V HOMO Source PSIO bowl ep For runs typically longer than 500 feet OOO S A B Figure 9 2 Nexus Meter C
87. etail by touching IN or OUT 40 4 20 4 a 16 32 48 64 BO 96 112 128 POLLING VOLTS A ZOOM E REAL TIME TRENDING ANALYSIS Select Channel by touching the CHANNEL button The Channel Selector screen shown below appears Select a Channel and touch OK to select channel and return to this screen Trending for the Selected REAL TIME TRENDING ANALYSIS VOLTS 1447 115 86 Channel will begin on this screen 571 To see a Detail of logs for the Selected Channel ei touch the DETAIL Button A Table of Logs for the 00 00 OOOO 00 00 00 00 00 00 13 52 15 52 Selected Channel appears Volts AN shown below Geen VOLTS An Weg Touch PREVIOUS LOGS to view other logs gt llos M REAL TIME TRENDING CHANNEL A UE Es 3 52 vu SELECTOR CHANNEL SELECTOR Sel Ch lb hi CHANNEL B Data will be lost if channel is changed elect Channel by touching a utton The Active Channel appears at the lower right ovsa ours as Data from the previously Active Channel will VOLTS BN VOLTS BC be lost if the Channel is changed VOLTS CN VOLTS CA The Time Interval for Trending appears at the FREQ WATTS Active Channel bottom of the screen To increase the Interval VOLTS AN touch the UP button To decrease the Interval POLUNG touch DN Down MAIN OK Pere UR DN Touch OK to return to Trending Analysis screen TEAC TIME TRENDING 3 52 PM VOLTS AN VOI TS E REAL TIME TRENDING DETAIL DAY TME LOG
88. evice Profile e Use the worksheet found in Chapter 7 Three Element Loss Compensation Worksheet to calculate the values by hand Notes under each section will assist you 1 Enter values based on the tranformer manufacturer s test report The worksheet is progressive and notes under each section will guide you to the next section 2 Enter the values into the Device Profile A 2 Excel Spreadsheet with Example Numbers E If you have MS Excel installed in your computer use the TLC Calculator button on the Transformer Loss screen of the Device Profile The copy of the Spreadsheet with Example Numbers found on the following pages will assist you G Electro Industries GaugeTech Doc E107706 V1 25 A 1 Electro Industries Gaugetech Westbury NY 877 EIMETER 877 346 3837 Nexus Transformer Loss Compensation Calculation Three Element Meter with 3 Wye connected PT s and 3 CT s Company Substation ________ Name Stn Tif Bank No Date TiMant E IR Loss Factors for Nx Communicator Software Calc Used AA AAA XV Low fT VV Tert PA Transformer Test Data Calculated Calc kVA No Load Loss Watts po Y 0 00 000 Full Load Loss Watts ll 0 00 000 Exciting Current ES Impedance_________ ________ OOOO Phase Phase Calculated Self Cooled kVA Rating A 0 Phase to Phase Phase to Grd Test Voltage SETA Full Load Current DIV 0 Meter Installation Data
89. exus 1250 1252 Monitor The Nexus 1250 1252 Monitor supports up to four HO modules using internal power Use the additional power supply EIG PSIO to extend I O capability See section 3 4 for mounting diagrams See Chapter 9 for details on installation and usage of the Nexus External I O Modules E Analog Transducer Signal Outputs Up to two modules can be used with the Nexus 1250 1252 1mAON4 4 Analog Outputs self powered scalable bidirectional e ImAON8 8 Analog Outputs self powered scalable bidirectional e 20mAONS4 4 Analog Outputs self powered scalable e 20mAON8 8 Analog Outputs self powered scalable E Analog Transducer Inputs Multiple modules can be used e AII 8 Analog Inputs 0 1mA scalable and bidirectional e HAD 8 Analog Inputs 0 20mA scalable e 8AI3 8 Analog Inputs 0 5V DC e HAL 8 Analog Inputs 0 10V DC E Digital Dry Contact Relay Outputs Multiple modules can be used e 4RO1 4 Relay Outputs 10 Amps 125V AC 30V DC Form C M Digital Solid State Pulse Outputs Multiple modules can be used e 4PO1 4 Solid State Pulse Outputs Form A KYZ pulses M Digital Inputs Multiple modules can be used e MIDI 8 Digital status inputs Wet Dry Auto Detect up to 300V AC DC B Other I O Accessories e PSIO Additional power supply for up to six I O modules This unit is necessary if you are connecting more than four I O modules to a Nexus 1250 1252 Monitor e MBIO Bracket for surface mounting I O mo
90. exus 1250 1252 Monitor at any given time You may retrieve them one at a time a new calendar can be stored while a current calendar is in use Accumulations do not stop during calendar updates If a calendar is replaced while in use the accumulations for the current period will continue until the set end date At that point the current time will become the new start time and the settings of the new calendar will be used Reset the current accumulations if you replace a calendar in use A reset clears only the current accumulation registers This causes the current accumulations to use the present date as the start and accumulate to the next new end date which will be taken from the new calendar Once stored prior accumulations are always available and can not be reset See the Nexus Communicator User Manual for how to reset TOU accumulations At the end of a defined period current accumulations are stored the registers are cleared and accumulations for the next period begin When the year boundary is crossed the second calendar if present is used To retain continuity you have up to one year to replace the old calendar with one for the following year 8 5 Daylight Savings and Demand To use Daylight Savings Time you must enable it in the Nexus Monitor s Device Profile Time Settings Click Auto DST which sets Daylight Savings Time automatically for the United States ONLY You can also select User Defined and enter the desired date
91. exus P40N P41N P43N LED External Display Specifications Specification Nexus P40N P41N P43N LED External Display Maximum Input Voltage 30V DC Minimum Input Voltage TV DC Maximum Power Consumption 8 Watts Nominal Power Consumption Approximately 6 Watts Operating Temperature Range 40 C to 80 C 40 F to 176 F Overall Dimensions HxWxL 2 2 x 4 4 x 4 4 in 5 9 x 11 1 x 11 1 cm 2 11 Nexus P60N Touch Screen Display Specifications Specification Nexus P60N Touch Screen Display Maximum Input Voltage 30V DC Minimum Input Voltage 10V DC Maximum Power Consumption 5 Watts Nominal Power Consumption Approximately 4 5 Watts Operating Temperature Range 0 C to 50 C 32 F to 122 F Overall Dimensions HxWxL 1 6 x 5 4 x 8 0 in 4 0 x 13 7 x 20 3 cm Electro Industries GaugeTech Doc E107706 V1 25 2 14 Chapter 3 Hardware Installation 3 1 Mounting the Nexus 1250 1252 Meter M The Nexus 1250 1252 Meter is designed to mount against any firm flat surface Use a 10 screw in each of the four slots on the flange to ensure that the unit is installed securely For safety reasons mount the Meter in an enclosed and protected environment such as in a switchgear cabinet Install a switch or circuit breaker nearby label it clearly as the meter s disconnecting mechanism NOTE The Nexus Meter with Internal Modem Option mounts the same way MW Maintain the following conditions e Operating Temperature 40 C to 70 C 40 F to 15
92. format This version is not dependent upon strict timing as is the RTU version This is the best choice for telecommunications applications via modems The most common form of Modbus protocol Modbus RTU is an open protocol spoken by many field devices to enable devices from multiple vendors to communicate in a common language Data is transmitted in a timed binary format providing increased throughput and therefore increased performance A communications connection between two or more devices to enable those devices to send and receive data to one another In most applications the network will be either a serial type or a LAN type Nonvolatile Random Access Memory is able to keep the stored values in memory even during the loss of circuit or control power High speed NVRAM is used in the Nexus to gather measured information and to insure that no information is lost A port that facilitates infrared communication with a 1260 1270 meter Using an ANSI C12 13 Type II magnetic optical communications coupler and an RS 232 cable from the coupler to a PC the meter can be programmed with Nexus Communicator software A short fixed length section of data that is transmitted as a unit Example a serial string of 8 bit bytes Percent Total Harmonic Distortion See THD A language that will be spoken between two or more devices connected on a network Potential Transformer Ratio used to scale the value of the voltage to the primary side
93. frequencies that are multiples of the fundamental 60 Hz frequency This modeling is performed by mathematically disassembling the distorted waveform into a collection of higher frequency waveforms These higher frequency waveforms are referred to as harmonics Figure 1 12 shows the content of the harmonic frequencies that make up the distortion portion of the waveform in Figure 1 11 Expanded Harmonic Currents 250 200 150 100 Amps o 100 150 200 250 e 2 Harmonic Current 3 Harmonic Current a D Harmonic Current X 7 Harmonic Current gt A Current Total Hrm Figure 1 12 Waveforms of the Harmonics The waveforms shown in Figure 1 12 are not smoothed but do provide an indication of the impact of combining multiple harmonic frequencies together When harmonics are present it is important to remember that these quantities are operating at higher frequencies Therefore they do not always respond in the same manner as 60 Hz values G Electro Industries GaugeTech Doc E107706 V1 25 1 11 M Inductive and capacitive impedance are present in all power systems We are accustomed to thinking about these impedances as they perform at 60 Hz However these impedances are subject to frequency variation Au joL and Xc 1 0C At 60 Hz 377 but at 300 Hz Gi harmonic 1 885 As frequency changes impedance changes and syste
94. g I O Modules Manual 9 6 2 Normal Mode E In Normal Mode the Input Module 1 Reads and averages the A D and adjusts values for process 2 2 Calculates the percentage of Input Value NOTE The percentage value of the Input will be stored in Input Value Registers Registers 04097 04104 M The device will operate with the following default parameters Address 247 F7H Baud Rate 57600 Baud Transmit Delay Time 0 E Normal Operation is prevented by a number of occurrences See section 9 4 1 for details G Electro Industries GaugeTech Doc E107706 V1 25 9 10 9 7 Digital Dry Contact Relay Output Form C Module RS 485 Modbus RTU Communication Programmable Baud Rates 4800 9600 19200 57600 15 20V q at 50 200 mA Power Requirement Nexus 1250 1252 Unit supports up to 4 Modules GE 9 7 1 Overview The Relay Output Module consists of four Latching Relay Outputs In Normal Mode the device accepts commands to control the relays Relay output modules are triggered by limits programmed with the Communicator EXT software See the Communicator EXT User Manual for details on programming limits Nexus 1250 1252 Unit supplies power for up to 4 connected Relay Output modules See section 9 2 for power and communication details Refer to sections 5 12 5 13 to determine if you must use an additonal power source such as the EIG PSIO The Modbus Map for the Analog Output Module and operating details can be found in the
95. g RS 485 is viable for up to 4000 feet 1219 meters You must use an RS 485 to RS 232 converter such as EIG s Unicom 2500 See sections 5 7 1 For information on connecting the Nexus Meter to a modem see sections 5 14 5 16 Do not use the V V pins they supply power to the Nexus Displays and Nexus I O Modules 5 5 RJ 11 Telephone Line Connection Nexus with Internal Modem Option to a PC Use RJ 11 Standard Telephone Line to connect with the Nexus 1250 1252 The RJ 11 line is inserted into the RJ 11 Port on the face of the Nexus with Internal Modem Option The length of the connection using RJ 11 into the Nexus 1250 1252 is virtually unlimited To connect with other Nexus 1250 1252 Meters in either local or remote locations you MUST use Port 2 as a Master and an RS 485 connection The link using RS 485 is viable for up to 4000 feet 1219 meters For more information on the Nexus Meter with the Internal Modem Option see Chapter 10 of this manual 5 6 RJ 45 Connection Nexus with Internal Network Option to multiple PC s The Internal Network Option conforms to the IEEE 802 3 10BaseT specification using unshielded twisted pair UTP wiring This allows the use of inexpensive RJ 45 connectors and CAT 3 or better cabling Using this LAN connection allows multiple PC s to be connected concurrently The RJ 45 line is inserted into the RJ 45 Port on the face of the Nexus with Internal Network Option The connection usi
96. he interval is typically 15 minutes So the Average Watts is the thermal average of watts over the previous 15 minute interval The thermal average rises to 90 of the actual value in each time interval For example if a constant 100kW load is applied the thermal average will indicate 90kW after one time interval 99kW after two time intervals and 99 9kW after three time intervals A unit of computer information equivalent to the result of a choice between two alternatives Yes No On Off for example Or the physical representation of a bit by an electrical pulse whose presence or absence indicates data Relating to a system of numbers having 2 as its base digits O and 1 The Block Fixed Window Average is the average power calculated over a user set time interval typically 15 minutes This calculated average corresponds to the demand calculations performed by most electric utilities in monitoring user power demand See Rolling Window Average Glossary 1 Byte CBEMA Curve Channel CRC Field CT Current Ratio Demand Demand Interval Display DNP 3 0 EEPROM Energy Register Ethernet Exception Response Electro Industries Gauge Tech Doc E107706 V1 25 A group of 8 binary digits processed as a unit by a computer or device and used especially to represent an alphanumeric character A voltage quality curve established originally by the Computer Business Equipment Manufacturers Associat
97. he system is given by the algebraic sum of the readings of N wattmeters so arranged that each of the N wires contains one current coil the corresponding potential coil being connected between that wire and some common point If this common point is on one of the N wires the measurement may be made by the use of N 1 wattmeters The theorem may be stated more simply in modern language In a system of N conductors N 1 meter elements will measure the power or energy taken provided that all the potential coils have a common tie to the conductor in which there is no current coil Three phase power measurement is accomplished by measuring the three individual phases and adding them together to obtain the total three phase value In older analog meters this measurement was accomplished using up to three separate elements Each element combined the single phase voltage and current to produce a torque on the meter disk All three elements were arranged around the disk so that the disk was subjected to the combined torque of the three elements As a result the disk would turn at a higher speed and register power supplied by each of the three wires According to Blondell s Theorem it was possible to reduce the number of elements under certain conditions For example a three phase three wire delta system could be correctly measured with two elements two potential coils and two current coils if the potential coils were connected between the three phases
98. her voltages with the standard rating With Option G the direct voltage input is extended to 300V phase to neutral and 600V phase to phase 4 3 Wiring the Monitored Inputs VRef The Voltage Reference connection references the monitor to ground or neutral 4 4 Wiring the Monitored Inputs VAux The Voltage Auxiliary connection is an auxiliary voltage input that can be used for any desired purpose such as monitoring neutral to ground voltage or monitoring two different lines on a switch 4 5 Wiring the Monitored Inputs Currents Install the cables for the current at 600V AC minimum insulation The cable connector should be rated at 10 Amps or greater and have a cross sectional area of 14 AWG Mount the current transformers CTs as close as possible to the meter The following table illustrates the maximum recommended distances for various CT sizes assuming the connection is via 14 AWG cable G Electro Industries GaugeTech Doc E107706 V1 25 4 1 EIG Recommendations CT Size VA Maximum Distance from CT to Nexus Feet 120 WARNING DO NOT leave the secondary of the CT open when primary current is flowing This may cause high voltage which will overheat the CT If the CT is not connected provide a shorting block on the secondary of the CT E Itis important to maintain the polarity of the CT circuit when connecting to the Nexus If the polarity is reversed the Nexus will not provide accurate readings CT p
99. hort Time Flicker Phasor Limits NEXT gt Analysis NEXT aA Electro Industries GaugeTech Doc E107706 V1 25 Harmonic Spectrum Real Time P Analysis Waveform Graph NEXT Chapter 7 Transformer Loss Compensation 7 1 Introduction The Edison Electric Institute s Handbook for Electricity Metering Ninth Edition defines Loss Compensation as A means for correcting the reading of a meter when the metering point and point of service are physically separated resulting in measurable losses including IR losses in conductors and transformers and iron core losses These losses may be added to or subtracted from the meter registration Loss compensation may be used in any instance where the physical location of the meter does not match the electrical location where change of ownership occurs Most often this appears when meters are connected on the low voltage side of power transformers when the actual ownership change occurs on the high side of the transformer This condition is shown pictorially in Figure 7 1 Ownership Change Figure 7 1 Low Voltage Metering Installation Requiring Loss Compensation It is generally less expensive to install metering equipment on the low voltage side of a transformer and in some conditions other limitations may also impose the requirement of low side metering even though the actual ownership change occurs on the high voltage side The need for loss compensated me
100. ignal g M lt Generating M x Device Figure 5 21 IRIG B Connection m Installation 1 Set Time Settings for the meter being installed From Communicator EXT Device Profile Click Time Settings Set the Time Zone and Daylight Savings Select AutoDST or Enable and set dates Click Update Device Profile to save the new settings See the Communicator EXT User s Manual for details 2 Before connection check that the date on the meter clock is correct or within 2 MONTHS of the actual date This provides the right year for the clock GPS does not supply the YEAR 3 Connect the terminal of the Meter to the terminal of the signal generating device Connect the terminal of the Meter to the terminal of the signal generating device E Troubleshooting Tip The most common source of problems is a reversal of the two wires Try reversing the wires G Electro Industries GaugeTech Doc E107706 V1 25 5 25 G Electro Industries GaugeTech Doc E107706 V1 25 5 26 Chapter 6 Using the Nexus External Displays 6 1 Overview Electro Industries offers four external displays for use with the Nexus 1250 1252 The P40N P41N and P43N are LED displays that provide easy to use access to the information stored in the Nexus 1250 1252 The P60N is our Touch Screen Display which provides easy access to Nexus 1250 1252 readings and information combined with a graphical touch screen presentation Plug one of the Nexus External Displ
101. ion The CBEMA Curve defines voltage disturbances that could cause malfunction or damage in microprocessor devices The curve is characterized by voltage magnitude and the duration which the voltage is outside of tolerance See ITIC Curve The storage of a single value in each interval in a load profile Cyclic Redundancy Check Field Modbus communication is an error checksum calculation that enables a Slave device to determine if a request packet from a Master device has been corrupted during transmission If the calculated value does not match the value in the request packet the Slave ignores the request A Current Transformer Ratio is used to scale the value of the current from a secondary value up to the primary side of an instrument tranformer The average value of power or a similar quantity over a specified period of time A specified time over which demand is calculated User configurable visual indication of data in a meter A robust non proprietary protocol based on existing open standards DNP 3 0 is used to operate between various systems in electric and other utility industries and SCADA networks Nexus 1250 supports Level 1 Nexus 1252 supports Level 2 Nonvolatile memory Electrically Erasable Programmable Read Only Memory that retains its data during a power outage without need for a battery Also refers to meter s FLASH memory Programmable record that monitors any energy quantity Example Watthours VARhours VAho
102. ion that is experienced by the human visual system when it is subjected to changes occurring in the illumination intensity of light sources The primary effects of flicker are headaches irritability and sometimes epilepsy IEC 61000 4 15 and former IEC 868 describe the methods used to determine flicker severity This phenomenon is strictly related to the sensitivity and the reaction of individuals It can only be studied on a statistical basis by setting up suitable experiments among people 12 2 Theory of Operation Flicker can be caused by voltage variations which are caused by variable loads such as arc furnaces laser printers and microwave ovens In order to model the eye brain change which is a complex physiological process the signal from the power network has to be processed while conforming with Figure 16 1 below e Block 1 consists of scaling circuitry and an automatic gain control function that normalizes input voltages to Blocks 2 3 and 4 For the specified 50 Hz operation the voltage standard is 230 V RMS e Block 2 recovers the voltage fluctuation by squaring the input voltage scaled to the reference level This simulates the behavior of a lamp e Block 3 is composed of a cascade of two filters and a measuring range selector In this implementation a log classifier covers the full scale in use so the gain selection is automatic and not shown here The first filter eliminates the DC component and the double mains frequency co
103. ipment Power Multiplier G Electro Industries GaugeTech Doc E107706 V1 25 ABC Power Company Substation Name Has Engineer gt gt gt Sin TrfBankNoji31 Date 2414 2002 Electro Industries Gauge Tech Westbury NY 877 EIMETER 877 346 3837 Nexus Line Loss Compensation Calculation Three Element Meter with 3 Wye connected PT s and 3 CT s Substation _____ Name Stn Trf Bank No Date Metering Point Information Loss Factors Loss Factors for Nx Communicator Software Used Full Load Loss Watts LWCU DIV 0 DIV Full Load Loss VARS LVCU FDIV O DIVO Transmission Line Impedance Data Quantity PU Value A 7 R X o i O MVABase oT CCC Nominal Voltage Meter Installation Data Potential Trf ee Current tt O Power Multiplier Meter Secondary Voltage 120 volts for Nexus Meter Secondary Current 5 5Samps for Nexus 1 Ph kW Full Load Loss Watts TI 0 00 Full Load LossVARs_____ ______ OO Phase to Phase Phase to Grd Test Voltage CT Full Load Current DIV O Publishing and duplicating rights are property of Electro Industries Gaugetech This spreadsheet is designed only to be used with EIG Nexus based metering equipment G Electro Industries GaugeTech Doc E107706 V1 25 Electro Industries GaugeTech Westbury NY 377 EIMETER 877 346 3837 Nexus Line Loss Compensation Calculati
104. itching Capacitor switching Load switching Sag swell RMS voltage BEER Remote system faults duration System protection RMS voltage multiple second or Circuit breakers longer duration Fuses Maintenance Oscillatory transient Transient voltage sub cycle with decay duration Interruptions RMS voltage steady state Motor starting multiple second or longer Load variations duration Load dropping Undervoltage Overvoltage Intermittent loads Motor starting Arc furnaces eet Steady state current or voltage Non linear loads Harmonic distortion d long term duration System resonance Table 1 3 Typical Power Quality Problems and Sources RMS voltage steady state Voltage flicker eps S repetitive condition E It is often assumed that power quality problems originate with the utility While it is true that may power quality problems can originate with the utility system many problems originate with customer equipment Customer caused problems may manifest themselves inside the customer location or they may be transported by the utility system to another adjacent customer Often equipment that is sensitive to power quality problems may in fact also be the cause of the problem If a power quality problem is suspected 1t is generally wise to consult a power quality professional for assistance in defining the cause and possible solutions to the problem G Electro Industries GaugeTech Doc E107706 V1 25 1 13
105. m impedance characteristics that are normal at 60 Hz may behave entirely different in presence of higher order harmonic waveforms Traditionally the most common harmonics have been the low order odd freguencies such as the 3rd sth 7th and 9th However newer new linear loads are introducing significant quantities of higher order harmonics M Since much voltage monitoring and almost all current monitoring is performed using instrument transformers the higher order harmonics are often not visible Instrument transformers are designed to pass 60 Hz quantities with high accuracy These devices when designed for accuracy at low frequency do not pass high frequencies with high accuracy at frequencies above about 1200 Hz they pass almost no information So when instrument transformers are used they effectively filter out higher frequency harmonic distortion making it impossible to see M However when monitors can be connected directly to the measured circuit such as direct connection to 480 volt bus the user may often see higher order harmonic distortion An important rule in any harmonics study is to evaluate the type of equipment and connections before drawing a conclusion Not being able to see harmonic distortion is not the same as not having harmonic distortion M Iris common in advanced meters to perform a function commonly referred to as waveform capture Waveform capture is the ability of a meter to capture a present picture of the voltag
106. mponents of the demodulated output The configuration consists of a 05 Hz Low High Pass filter and a 6 Pole Butterworth Low Pass filter located at 35 Hz The second filter is a weighting filter that simulates the response of the human visual system to sinusoidal voltage fluctuations of a coiled filament gas filled lamp 60 W 230 V The filter implementation of this function is as specified in IEC 61000 4 15 e Block 4 is composed of a squaring multiplier and a Low Pass filter The Human Flicker Sensation via lamp eye and brain is simulated by the combined non linear response of Blocks 2 3 and 4 e Block 5 performs an online statistical cumulative probability analysis of the flicker level Block 5 allows direct calculation of the evaluation parameters Pst and Plt M Flicker Evaluation occurs in the following forms Instantaneous Short Term or Long Term Each form is detailed below G Electro Industries GaugeTech Doc E107706 V1 25 12 1 e Instantaneous Flicker Evaluation An output of 1 00 from Block 4 corresponds to the Reference Human Flicker Perceptibility Threshold for 50 of the population This value is measured in Perceptibility Units PU and is labeled Pinst This ia a real time value and it is continuously updated e Short Term Flicker Evaluation An output of 1 00 from Block 5 corresponding to the Pst value corresponds to the conventional threshold of irritability per IEC 1000 3 3 In order to evaluate flicker severity t
107. n down into Readings e Use the MODE button to scroll between Modes e Use the UP DOWN arrows to scroll from Group to Group within each Mode e Use the LEFT RIGHT arrows to scroll from Reading to Reading within each Group B Use the Communicator EXT software to Flash Update the P40N External Display G Electro Industries GaugeTech Doc t E107706 V1 25 6 2 6 3 Dynamic Readings Mode The External Display puts itself in the Dynamic Readings Mode upon power up Use the MODE button to access the Dynamic Readings from other Modes Use the UP DOWN arrows to navigate from Group to Group within this Mode See section 6 4 for a navigational map of the Dynamic Readings Mode Group 1 Phase to Neutral Voltages Use the LEFT RIGHT arrows to access the following readings in order Volts AN BN CN Maximum Volts AN BN CN Minimum Volts AN BN CN Volts AN BN CN THD Volts AN BN CN Maximum THD Volts AN BN CN Minimum THD Group 2 Phase to Phase Voltages Use the LEFT RIGHT arrows to access the following readings in order e Volts AB BC CA e Maximum Volts AB BC CA e Minimum Volts AB BC CA Group 3 Current Use the LEFT RIGHT arrows to access the following readings in order Current A B C Maximum Current Minimum Current Current THD Current Maximum THD Current Minimum THD Current Calculated N Measured N Maximum Current Calculated N Measured N Group 4 Watt VAR Use the LEFT RIGHT arrows to access the following readings in or
108. n factor the working of the Predictive Window Demand could be described as follows At 12 10 we have the average of the subintervals from 11 55 12 00 12 00 12 05 and 12 05 12 10 In five minutes 12 15 we will have an average of the subintervals 12 00 12 05 and 12 05 12 10 which we know and 12 10 12 15 which we do not yet know As a guess we will use the last subinterval 12 05 12 10 as an approximation for the next subinterval 12 10 12 15 As a further refinement we will assume that the next subinterval might have a higher average 120 than the last subinterval As we progress into the subinterval for example up to 12 11 the Predictive Window Demand will be the average of the first two subintervals 12 00 12 05 12 05 12 10 the actual values of the current subinterval 12 10 12 11 and the predistion for the remainder of the subinterval 4 5 of the 120 of the 12 05 12 10 subinterval of Subintervals n Subinterval Length Len Partial Subinterval Length Cnt Prediction Factor Pct Sub Y Sub Subo Partial Predict Len Len Len Cnt Len Len 1 Y Value Sub Len Cnt 1 Y Value Partial H nt n Len n 2 Y Value L Cnt Partial E x f x ra n Sub 2 Dk A Sub Sub e Len Cnt Pe n 1 2x n 1 Len Electro Industries GaugeTech Doc E107706 V1 25 2 11 2 8 Nexus External 1 0 Modules Optional The following multiple analog or digital I O modules mount externally to the N
109. n to First Reading Return to First Reading 6 Electro Industries GaugeTech Doc E107706 V1 25 6 5 Nexus Information Mode IE Use the MODE button to access the Nexus Information Mode from other Modes Use the UP DOWN arrows to navigate from Group to Group within this Mode See section 6 6 for a navigational map of the Nexus Information Mode E Group 1 Device Time e Meter Time E Group 2 Communication Settings Use the LEFT RIGHT arrows to access the following readings in order Communication Settings Port 1 Baud Addr Protocol Communication Settings Port 2 Baud Addr Protocol Communication Settings Port 3 Baud Addr Protocol Communication Settings Port 4 Baud Addr Protocol B Group 3 PT CT Ratios Use the LEFT RIGHT arrows to access the following readings in order e PT Ratio e CT Ratio E Group 4 External Display Units e Primary Secondary e Select either Primary or Secondary units for the External Display using the Communicator EXT software see the Energy Manager User Manual When Primary is selected the Display shows all readings in Primary units based on the user programmed PT and CT Ratios When Secondary is selected the Display shows all readings in Secondary units E Group 5 Firmware Versions and Serial Numbers Use the LEFT RIGHT arrows to access the following readings in order e Run Time External Display Run Time DSP RunTime Comm e Boot External Display Boot DSP Boot Comm e Serial Number Ext
110. necessary for the computer to ensure connection with the originate modem Set modem to enable Flow Control This is necessary to communicate with remote modem connected to the Nexus Tell modem to write the new settings to activate profile This places these settings into nonvolatile memory the setting will take effect after the modem powers up IE Modem Connected to the Nexus Meter the Remote Modem Restore modem to factory settings This erases all previously programmed settings Set modem to auto answer on N rings This sets the remote modem to answer the call after N rings Set modem to ignore DTR Signal This is necessary for the Nexus to ensure connection with originate modem Set modem to disable Flow Control Nexus RS 232 communication does not support this feature Tell modem to write the new settings to activate profile This places these settings into nonvolatile memory the setting will take effect after the modem powers up When programming the remote modem with a terminal program make sure the baud rate of the terminal program matches the Nexus Meter s baud rate G Electro Industries GaugeTech Doc E107706 V1 25 5 22 5 20 Selected Modem Strings Modem Cardinal modem Zoom Faxmodem VFX V 32BIS 14 4K Zoom Faxmodem 56Kx Dual Mode USRobotics Sportster 33 6 Faxmodem DIP switch setting USRobotics Sportster 56K Faxmodem DIP switch setting 5 21 High Speed Inputs Connection String Setting AT am
111. neutral or center point of the wye is typically grounded This leads to common voltages of 208 120 and 480 277 where the first number represents the phase to phase voltage and the second number represents the phase to ground voltage Phase B N D Phase C g Phase A Figure 1 1 Three Phase Wye Winding E The three voltages are separated by 120 electrically Under balanced load conditions with unity power factor the currents are also separated by 120 However unbalanced loads and other conditions can cause the currents to depart from the ideal 120 separation G Electro Industries GaugeTech Doc E107706 V1 25 1 1 Three phase voltages and currents are usually represented with a phasor diagram A phasor diagram for the typical connected voltages and currents is shown in Figure 1 2 Fig 1 2 Phasor Diagram Showing Three phase Voltages and Currents M The phasor diagram shows the 120 angular separation between the phase voltages The phase to phase voltage in a balanced three phase wye system is 1 732 times the phase to neutral voltage The center point of the wye is tied together and is typically grounded Table 1 1 shows the common voltages used in the United States for wye connected systems Phase to Ground Voltage Phase to Phase Voltage 120 volts 208 volts 277 volts 480 volts 2 400 volts 4 160 volts 7 200 volts 12 470 volts 7 620 volts 13 200 volts Table 1 1 Common Phase Voltages on Wye Services
112. ng RJ 45 into the Nexus 1250 1252 can connect the Nexus to a network using Modbus TCP protocol over Ethernet To connect with other Nexus Meters in either local or remote locations you MUST use Port 2 which is labeled Ethernet Gateway as a Master and an RS 485 connection The link using RS 485 is viable for up to 4000 feet 1219 meters For more information on the Nexus 1250 1252 Meter with the Internal Network Option see Chapter 11 of this manual Electro Industries GaugeTech Doc E107706 V1 25 5 8 5 7 RS 485 Connection Nexus to an RS 485 Master Unicom or Modem Manager M To establish communication between a Nexus Meter and any RS 485 master such as EIG s Unicom 2500 Modem Manager or other RS 232 485 converter use a shielded twisted pair cable IE Use an RS 485 port Ports 1 4 on the Nexus Meter If you use Port 1 set the selector switch beneath it to RS 485 see Figure 5 3 Connect the A and B terminals on the Nexus to the and terminals on the master Provide jumpers on the master linking its two terminals and two terminals RS 485 communication is viable for up to 4000 feet 1219 meters IE Connect the shield to the Ground G terminal on the Master The S terminal on the Nexus is used to reference the Nexus port to the same potential as the source It is not an earth ground connection You must also connect the shield to earth ground at one point NOTE Refer to section 5 3 for information on
113. ngs provided are the number and length of demand subintervals At every subinterval an average arithmetic mean of power readings over the subinterval is internally calculated This new subinterval average is then averaged arithmetic mean with as many previous subinterval averages as programmed to produce the Rolling Window Demand Example With settings of 3 five minute subintervals subinterval averages are computed every 5 minutes 12 00 12 05 12 15 etc for power readings over the previous five minute interval 11 55 12 00 12 00 12 05 12 05 12 10 12 10 12 15 etc Further every 3 minutes the subinterval aver ages are averaged in groups of 3 12 00 12 05 12 10 12 15 etc to produce a fifteen 5x3 minute average every 5 minutes rolling sliding every 5 minutes 11 55 12 10 12 00 12 15 etc Predictive Window Demand Predictive Window Demand enables the user to forecast average demand for future time intervals The Nexus uses the delta rate of change of a Rolling Window Demand interval to predict average demand for an approaching time period The user can set a relay or alarm to signal when the Predictive Window reaches a specific level thereby avoiding unacceptable demand levels The Nexus 1250 1252 calculates Predictive Window Demand using the following formula Electro Industries GaugeTech Doc E107706 V1 25 2 10 Example Using the previous settings of 3 five minute intervals and a new setting of 120 predictio
114. nt of the load rises above a specified value A common method of measuring reactive power requirements is power factor Power factor can be defined in two different ways The more common method of calculating power factor is the ratio of the real power to the apparent power This relationship is expressed in the following formula Total PF real power apparent power watts VA This formula calculates a power factor quantity known as Total Power Factor It is called Total PF because it is based on the ratios of the power delivered The delivered power quantities will include the impacts of any existing harmonic content If the voltage or current includes high levels of harmonic distortion the power values will be affected By calculating power factor from the power values the power factor will include the impact of harmonic distortion In many cases this is the preferred method of calculation because the entire impact of the actual voltage and current are included A second type of power factor is Displacement Power Factor Displacement PF is based on the angular relationship between the voltage and current Displacement power factor does not consider the magnitudes of voltage current or power It is solely based on the phase angle differences As a G Electro Industries GaugeTech Doc E107706 V1 25 1 9 result it does not include the impact of harmonic distortion Displacement power factor is calculated using the following equation Dis
115. nted device Autocalibrates when there is a temperature change of more than 10 degrees centigrade Exceeds all ANSI C 12 and IEC 687 specifications Adjusts for transformer and line losses using user defined compensation factors Automatically logs time of use for up to eight programmable tariff registers Counts pulses and aggregates different loads M Nexus 1250 1252 Power Quality Monitoring e Records up to 512 samples per cycle on an event Records sub cycle transients on voltage or current readings Measures and records Harmonics to the 83rd order Offers inputs for neutral to ground voltage measurements Synchronizes with IRIG B clock signal E Nexus 1250 1252 Memory Communication and Control Up to 4 Meg NVRAM 4 High Speed Communication Ports Multiple Protocols see section below on DNP V3 00 Built in RTU functionality Built in PLC functionality 90msec High Speed Updates for Control 2 2 DNP V3 00 Level 1 and Level 2 Nexus 1250 supports DNP V3 00 Level 1 Nexus 1252 supports DNP V3 00 Level 2 DNP Level 2 Features e Up to 136 measurement 64 Binary Inputs 8 Binary Counters 64 Analog Inputs can be mapped to DNP Static Points over 3000 in the customizable DNP Point Map Up to 16 Relays and 8 Resets can be controlled through DNP Level 2 Report by Exception Processing DNP Events Deadbands can be set on a per point basis Freeze Commands Freeze Freeze No Ack Freeze with Time Freeze with Time No Ack Freez
116. ntire password is shown on the Display screen press ENTER If the password is correct you may then press Enter again to Reset the Energy readings e Press the Enter button to reset the Max and Min values Group 2 Reset Energy e Note If the password protection feature has been enabled with the Communicator EXT software you will need to enter a password to reset the energy To do this first press the Enter button Then enter the password one character at a time by pressing on the UP or DOWN arrows Each password character begins as an A Press the UP arrow to increment the character from A Z and then from 0 9 Press the DOWN arrow to decrement the character from A to 9 0 and then from Z A Press SET to enter each character the password When the entire password is shown on the Display screen press ENTER If the password is correct you may then press Enter again to Reset the Energy readings e Press Enter button to reset the Max and Min values Group 3 Display Baud Rate Address Group 4 Display Communication Protocol Group 5 EIG Use Only Group 6 EIG Use Only Group 7 Lamp Test e Press Enter to conduct an LED test Group 8 Display Scroll ON OFF e Press Enter to turn the scroll feature on or off When the scroll feature is on the P40N External Display will scroll through the first reading of each group in the Dynamic Readings Mode If a button is pressed during the scroll scrolling pauses for
117. nts Communicates using the industry standard Modbus TCP protocol 2 5 2 Hardware Connection B Use Standard RJ 45 10 100BaseT cable to connect with the Nexus The RJ 45 line is inserted into the RJ 45 Port on the face of the Nexus with IMP100 Ethernet Option E To make the software connection use the following steps 1 Using Port 1 or Port 4 RS 485 connection connect a PC to the meter An RS 232 RS 485 Converter may be required Example Electro Industries Unicom 2500 Double click on Communicator EXT Software to open Click the Quick Connect or the Connection Manager icon in the icon tool bar Click the Serial Port button Make sure data matches the meter then click Connect E Set the Network Settings using the following steps Refer to Section 3 6 of the Communicator EXT User Manual for more details 1 From the Device Profile screen double click on the Communications Ports line then double click on any of the ports The Device Profile Communications Settings screen appears Electro Industries GaugeTech Doc E107706 V1 25 2 4 2 If you are going to use DHCP click the Advanced Settings Button Click the tab at the top of the DHCP screen Click Enable DHCP will automatically enter the IP Address and some or all of the Interface Settings Click OK at the bottom of the screen to return to the Device Profile Communication Ports screen You may have to manually enter DNS Email Gateway Setting and or a Unique
118. of an instrument transformer Also referred to as VT Ratio The closing and opening of the circuit of a two wire pulse system or the alternate closing and opening of one side and then the other of a three wire system which is equal to two pulses Watt and VAR flow is typically represented usng an X Y coordinate system The four corners of the X Y plane are referred to as quadrants Most power applications label the right hand corner as the first quadrant and number the remaining quadrants in a counter clockwise rotation Following are the positions of the quadrants 1st upper right 2nd upper left 3rd lower left and 4th lower right Power flow is generally positive in quadrants 1 and 4 VAR flow is positive in quadrants 1 and 2 The most common load conditions are Quadrant 1 power flow positive VAR flow positive inductive load lagging or positive power factor Quadrant 2 power flow negative VAR flow positive capacitive load leading or negative power factor Glossar y 4 Register Register Rollover Reset Rolling Window Average Power RS 232 RS 485 Sag Secondary Rated Serial Port Slave Device Swell G Electro Industries Gauge Tech Doc E107706 V1 25 An entry or record that stores a small amount of data A point at which a Register reaches its maximum value and rolls over to zero Logs are cleared or new or default values are sent to counters or timers The Rolling Sliding Window A
119. olarities are dependent upon correct connection of CT leads and the direction CTs are facing when clamped around the conductors EIG recommends using shorting blocks to allow removal of the Nexus Meter from an energized circuit if necessary Shorting blocks are not required for proper meter operation 4 6 Isolating a CT Connection Reversal E Fora WYE System you may either 1 Check the current phase angle reading on the Nexus External Display see Chapter 6 If it is negative reverse the CTs 2 Or go to the Phasors screen of the Communicator EXT software see Communicator EXT User Manual Note the Phase Relationship between the Current and Voltage they should be in phase M For a DELTA System Go to the Phasors screen of the Communicator EXT software program The current should be 30 degrees off the phase to phase voltage 4 7 Instrument Power Connections BE The Nexus requires a separate power source To use AC power connect the line supply wire to the L terminal and the neutral supply wire to the N terminal on the Nexus To use DC power connect the positive supply wire to the L terminal and the negative ground supply wire to the N terminal on the Nexus Power supply options and corresponding suffixes are listed in the following table G Electro Industries GaugeTech Doc E107706 V1 25 4 2 Control Power Option Suffix E Do not ground the unit through the negative of the DC supply Separate grounding is required
120. on Example Three Element Meter with 3 Wye connected PT s and 3 CT s ABC Power Compan Substation Name Joe Engineer Stn Trf Bank No Small Station 138 Date 2414 2002 Metering Point Information Meter point is 45 miles down line from Big Station AA Loss Factors for Nx Communicator Software Calc Used FullLoad Loss VARs LVCU 0 01872 0 018 Transmission Line Impedance Data Quantity PUValue Value Used AR 00304 0 0304 A AY 01573 MVA Base 100 10 Meter Installation Data nstrument Transformers Numerator Denominator Multiplier Potential Trf 138000 1200 Current Tf _g0 5 180 Power Multiplier 216000 Meter Secondary Voltage 120 volts for Nexus Meter Secondary Current 5 5amps for Nexus 3PhLoss 1PhWatt 1 Ph kw Full Load Loss Watts 3 040 1013 33 Full Load Loss VARs 15 730 5243 33 Watts Loss at CT Full Load 14 068 Phase to Phase Phase to Grd Test Voltage 138000 79674 Full Load Current Publishing and duplicating rights are property of Electro Industries G augetech This spreadsheet is designed only to be used with EIG Nexus based metering equipment G Electro Industries GaugeTech Doc E107706 V1 25 A 5 G Electro Industries GaugeTech Doc E107706 V1 25 0 1 Second Values 1 Second Values Alarm Annunciator Average Current Average Input Pulse Accumulations Average Power Bit
121. one O Network NULL Modem Adapter or Null Cable Required Remote Connection RS 485 PC at office Originate Telephone Line Remote Nexus 1250 1252 Modem Modem Meter RS NULL Modem Adapter Required if 232 485 Converter does not support DTE DCE reconfiguration E to e onverter Modem Manager Recommended Figure 5 16 Remote Connections RS 232 RS 485 G Electro Industries GaugeTech Doc E107706 V1 25 5 18 IE Use RJ 11 Telephone Lines when devices are at great distances Connections are simple requiring no additional hardware RJ 11 a 000 000 000 000 NEXUS 1250 HT 0385088 Pp mea PC Originate Modem or Internal to PC Figure 5 17 Remote Connections with Internal Modem Option M Standard Telephone wall to phone cabling can be used This cabling is widely available in many lengths with RJ 11 plugs on each end E Plug one end into the Nexus 1250 1252 and the other end into the wall jack G Electro Industries GaugeTech Doc E107706 V1 25 5 19 E Or use RJ 45 Network Connection when devices are at great distances Connections are simple requiring no additional hardware RS 485 MODBUS RTU 10 100BaseT or 10BaseT LH MODBUS TCP over Ethernet EE ELE E ECG a 000 000 000 000 RE Del 6 e n COCOON MM ono gt Network Figure 5 18 Remote Connections with Internal Network Option G Electro Industries GaugeTech Doc E107706
122. one minute Electro Industries GaugeTech Doc E107706 V1 25 6 8 6 8 Navigational Map of Display Features Mode BE Use UP DOWN arrows to scroll between groups mOConbi G Electro Industries GaugeTech Reset Max Min Reset Energy Baud Rate Address Communication Protocol EIG Use Only EIG Use Only Lamp Test Display Scroll On Off Doc E107706 V1 25 6 9 Nexus P60N Touch Screen External Display M The P60N Touch Screen External Display is ready to use upon power up Touching the buttons at the top of the screen will take you to the Groups of Readings listed below With the buttons at the bottom of the screen you can use the touch screen to review Limits and review and or change Settings on the Display and the Nexus Meter Also you can Reset Max Min and Demand Hour PT and V T Counters All Logs and TOU for Current Session and Month using the Reset Button M All screens have a Main button that returns you to the Main screen below All screens also have a Next button that will take you to the next group of readings Some of the screens have additional navigation buttons to take you to complimentary readings See section 6 10 for a navigational map General Page ELECTRO INDUSTRIES 1 16 05 3 52 PM POWER MONITORING Groups of Readings METER DESIGNATION a SA PHASORS VOLTS DEMAND WAVEFORM AMPS ENERGY SPECTRUM ce TOU TREND FLICKER status
123. onnected to I O Module E NOTE Termination Resistors are only needed with runs typically more than 500 feet The meter has some level of termination internally and usually resistors are not needed G Electro Industries GaugeTech Doc E107706 V1 25 9 3 9 2 1 Power Source for 1 0 Modules M The Nexus 1250 1252 will supply power to a limited number 3 HO MODULES For more you must use an external power source such as the EIG PSIO 12V Refer to sections 5 12 and 5 13 to Determine Power Needed RS 485 communication is viable for up to 4000 feet 1219 meters You must also do the following 1 Connect the A and B terminals on the Nexus to the A and B terminals of the male RS 485 port Connect the shield to the shield S terminal The S terminal on the Nexus is used to reference the Nexus port to the same potential as the source It is not an earth ground connection You must also connect the shield to earth ground at one point 2 Put termination resistors at each end connected to the A and B lines RT is 120 Ohms NOTE Refer to section 5 3 for RT Explanation 3 Connect a source of power to the front of the module SIDE LABEL On Power In N L L Power Supply Max Power 12 VA Input Voltage 12 60V DC O 90 240V AC DC O Output Voltage 12V DC Electrolndustries Gauge Tech www electroind com TOP LABEL Figure 9 3 The PSIO Power Source Side View z showing Male RS 485 Side Port j
124. ons on a monthly basis Seasonal and monthly accumulations may span one year into the next Each season and month is defined by a programmable start billing date which is also the end date of the prior season or month e A season ends at midnight of the day before the start of the next season e A month ends at midnight of the month s billing day If the year ends and there is no new calendar TOU accumulations will stop If a calendar is present for the following year TOU accumulations continue until the next monthly bill date or next start of season is reached Accumulation can span into the following year If no following year is present the last accumulation for the year will end on 12 31 23 59 59 Electro Industries GaugeTech Doc E107706 V1 25 8 1 8 3 TOU Prior Season and Month The Nexus 1250 1252 Monitor stores accumulations for the prior season and the prior month When the end of a billing period is reached the current season or month becomes stored as the prior The registers are then cleared and accumulations resume using the next set of TOU schedules and register assignments from the stored calendar Prior and current accumulations to date are always available 8 4 Updating Retrieving and Replacing TOU Calendars Communicator EXT software retrieves TOU calendars from the Nexus 1250 1252 Monitor or from the computer hard drive for review and edit Up to a maximum of twenty yearly calendars can be stored in the N
125. ount of active Watts and reactive VARs power lost due to both iron and copper effects reflected to the secondary of the instrument transformers Total Secondary Watt Loss Measured Voltage Cal point Voltage x LWFE Measured Current Cal Point Current x LWCU x Full scale Secondary VA Total Secondary VAR Loss Measured Voltage Cal point Voltage x LVFE Measured Current Cal Point Current x LVCU x Full scale Secondary VA The Values for LWFE LWCU LVFE LVCU are derived from the transformer and meter information as demonstrated in following sections The calculated loss compensation values are added to or subtracted from the measured Watts and VARs The selection of adding or subtracting losses is made through the meter profile when programming the meter The meter uses the combination of the add subtract setting and the directional definition of power flow also in the profile to determine how to handle the losses Losses will be added to or subtracted from depending on whether add or subtract is selected the Received Power flow For example 1f losses are set to Add to and received power equals 2000 kW and losses are equal to 20kW then the total metered value with loss compensation would be 2020 KW for these same settings if the meter measured 2000 kW of delivered power the total metered value with loss compensation would be 1980 kW Since transformer loss compensation is the more common loss compensa
126. ower measurement is intended to provide only a brief overview of the subject The professional meter engineer or meter technician should refer to more advanced documents such as the EEI Handbook for Electricity Metering and the application standards for more in depth and technical coverage of the subject 1 1 Three Phase System Configurations Three phase power is most commonly used in situations where large amounts of power will be used because it is a more effective way to transmit the power and because it provides a smoother delivery of power to the end load There are two commonly used connections for three phase power a wye connection or a delta connection Each connection has several different manifestations in actual use When attempting to determine the type of connection in use it is a good practice to follow the circuit back to the transformer that is serving the circuit It is often not possible to conclusively determine the correct circuit connection simply by counting the wires in the service or checking voltages Checking the transformer connection will provide conclusive evidence of the circuit connection and the relationships between the phase voltages and ground 1 1 1 Wye Connection M The wye connection is so called because when you look at the phase relationships and the winding relationships between the phases it looks like a wye Y Figure 1 1 depicts the winding relationships for a wye connected service In a wye service the
127. p FEOF8 amp KONOS37 9 AT amp FO amp KOSO 1 amp W0 amp YO AT amp FO amp KO amp COS0 1 amp W0 amp YO AT amp FO amp N6 amp WOYO for 9600 baud Up Up Down Down Up Up Up Down AT amp FO amp WOY0 Up Up Down Down Up Up Up Down M The Nexus High Speed Inputs can be used in many ways Attach the KYZ HS Outputs from other meters for totalizing Attach relaying contacts for breaker status or initiated logging M Refer to the Communicator EXT User Manual for information on programming the functionality of these versatile inputs M The High Speed Inputs can be used with either dry or wet field contacts For WET contacts the common rides on a unit generated 15V DC No user programming is necessary to use either wet or dry field contacts 8 7 6 O Optional 150V Max for wet contacts Figure 5 20 High Speed Inputs Connection Electro Industries GaugeTech Doc E107706 V1 25 5 23 5 22 Five Modes of Time Synchronization M The Nexus meter offers up to five modes of Time Synchronization depending on options selected at the time of ordering 1 Internal Crystal The Default Time Constant is an Internal Crystal The crystal is accurate to approximately 1 minute per month 2 Line Frequency The meter ignores the internal crystal and counts frequency to synchronize the clock This feature is highly accurate in the presence of reliable system frequency If power is lost the unit automatically switches to the internal crystal 3 Mod
128. placement PF cos 6 where 0 is the angle between the voltage and the current see Fig 1 9 In applications where the voltage and current are not distorted the Total Power Factor will equal the Displacement Power Factor But if harmonic distortion is present the two power factors will not be equal 1 4 Harmonic Distortion M Harmonic distortion is primarily the result of high concentrations of non linear loads Devices such as computer power supplies variable speed drives and fluorescent light ballasts make current demands that do not match the sinusoidal waveform of AC electricity As a result the current waveform feeding these loads is periodic but not sinusoidal Figure 1 10 shows a normal sinusoidal current waveform This example has no distortion A Phase Current 1500 1000 500 500 1000 1500 Figure 1 10 Nondistorted Current Waveform M Figure 1 11 shows a current waveform with a slight amount of harmonic distortion The waveform is still periodic and is fluctuating at the normal 60 Hz frequency However the waveform is not a smooth sinusoidal form as seen in Figure 1 10 G Electro Industries GaugeTech Doc E107706 V1 25 1 10 Total A Phase Current with Harmonics 1500 1000 500 500 1000 1500 Figure 1 11 Distorted Current Wave M The distortion observed in Figure 1 11 can be modeled as the sum of several sinusoidal waveforms of
129. r is required For customer or technical assistance repair or calibration phone 516 334 0870 or fax 516 338 4741 Product Warranty Electro Industries GaugeTech warrants all products to be free from defects in material and workmanship for a period of four years from the date of shipment During the warranty period we will at our option either repair or replace any product that proves to be defective To exercise this warranty fax or call our customer support department You will receive prompt assistance and return instructions Send the instrument transportation prepaid to EIG at 1800 Shames Drive Westbury NY 11590 Repairs will be made and the instrument will be returned Limitation of Warranty This warranty does not apply to defects resulting from unauthorized modification misuse or use for any reason other than electrical power monitoring Nexus 1250 1252 is not a user serviceable product OUR PRODUCTS ARE NOT TO BE USED FOR PRIMARY OVER CURRENT PROTECTION ANY PROTECTION FEATURE IN OUR PRODUCTS IS TO BE USED FOR ALARM OR SECONDARY PROTECTION ONLY THIS WARRANTY IS IN LIEU OF ALL OTHER WARRANTIES EXPRESSED OR IMPLIED INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE ELECTRO INDUSTRIES GAUGETECH SHALL NOT BE LIABLE FOR ANY INDIRECT SPECIAL OR CONSEQUENTIAL DAMAGES ARISING FROM ANY AUTHO RIZED OR UNAUTHORIZED USE OF ANY ELECTRO INDUSTRIES GAUGETECH PRODUCT LIABILITY SHALL BE LIMITED TO THE O
130. rements These voltages are measured between the three phase voltage inputs to the meter Voltage Van Van Vbn Ven are all Phase to Neutral voltages applied to the monitor These voltages are measured between the phase voltage inputs and Vn input to the meter Technologically these voltages can be measured even when the meter is in a Delta configuration and there is no connection to the Vn input However in this configuration these voltages have limited meaning and are typically not reported Voltage Vaux This is the fourth voltage input measured from between the Vaux and Vref inputs This input can be scaled to any value However the actual input voltage to the meter should be of the same magnitude as the voltages applied to the Va Vb and Vc terminals Electro Industries Gauge Tech Doc E107706 V1 25 Glossary 6
131. repeater connected in series via RS 485 daisy chain Telephone Line Fiber Optic Link or Radio Link RS 232 485 Converter Modem Manager Figure 5 1 Communication Overview Electro Industries GaugeTech Doc E107706 V1 25 5 1 M RJ 11 Telephone Line allows a Nexus Meter with the Internal Modem Option to communicate with a PC No other hardware is necessary for this easy to use connection The Nexus 1250 1252 Meter with the Internal Modem Option can connect via RS 485 to other Nexus Meters in local or remote sites in a daisy chain configuration as depicted below The Nexus Meter with the Internal Modem Option has a unique label Port 2 is labeled Modem Gateway If you are going to use RS 485 to connect multiple Nexus 1250 1252 meters you MUST use the Modem Gateway For more details see Chapter 10 of this manual RJ 11 NEXUS 1250 Pool 0385050 Originate Modem or Internal to PC Figure 5 2 RJ 11 Communication with Internal Modem Option Electro Industries GaugeTech Doc E107706 V1 25 5 2 E RJ 45 Network Connection allows a Nexus Meter with the Internal Network Option to communicate with multiple PC s concurrently No other hardware is necessary for this easy to use connection The Nexus Meter with the Internal Network Option can connect via RS 485 to other Nexus Meters in local or remote sites in a daisy chain configuration as depicted below The Nexus 1250 1252 Meter with
132. rt Reset and Stop times are all recorded All values can be down loaded to the Log Viewer where they are available for graphing or export to another program such as Excel All Flicker values are predefined and cannot be changed 12 6 Polling The Pinst Pst Pst Max Pst Min Plt Plt Max Plt Min values are all capable of being polled through the Communications Port Refer to the Nexus Modbus and DNP Mappings for register assignments and data definitions 12 7 Log Viewer From the Communicator EXT Log Viewer screen using the menus at the top of the Log Viewer screen select a meter time ranges and values to access Select Flicker The values and the associated time stamps when the values occurred are displayed in a grid box Use the buttons at the bottom of the screen to create a graph or export the data to another program Max and Min values are only displayed they cannot be graphed But Max and Min values are available for export Graphed values include Pst and Plt Va Vb and Ve Displayed values include Pst and Plt Max and Min for Va Vb and Vc G Electro Industries GaugeTech Doc E107706 V1 25 12 7 12 8 Performance Notes Pst and Plt average time are synchronized to the clock e g for a 10 minute average the times will occur at 0 10 20 etc The actual time of the first average can be less than the selected period to allow for initial clock synchronization If the wrong frequency is chosen e g 50Hz selection for a
133. s for Daylight Savings Time See the Communicator EXT User Manual for details To set Demand Intervals from the Device Profile select Demand Integration and set the desired intervals To set Cumulative Demand Type from the Device Profile click Cold Load Pickup and select Block or Rolling Window Average G Electro Industries GaugeTech Doc E107706 V1 25 8 2 Chapter 9 Nexus External UO Modules 9 1 Hardware Overview M All Nexus External I O modules have the following components e Female RS 485 Side Port use to connect to another modules male RS 485 side port e Male RS 485 Side Port use to connect to the Nexus 1250 1252 Meter s Port 3 or 4 or to another module s female RS 485 side port See Figure 9 2 for wiring detail e I O Port used for functions specific to the type of module size and pin configuration vary depending on type of module e Reset Button Press and hold for three seconds to reset the module s baud rate to 57600 and its address to 247 for 30 seconds e LEDs when flashing signal that the module is functioning e Mounting Brackets MBIO used to secure one or more modules to a flat surface Mounting Brackets MBIO LEDs 1 O Port Size and pin Integrated Fastening System configuration vary Male RS 485 Side Port Reset Button Figure 9 1 1 0 Module Components G Electro Industries GaugeTech Doc E107706 V1 25 9 1 9 1 1 Port Overview E All Electro Industries I O Modul
134. s recorded Clicking on Reset causes the Max Min values to be cleared and restarts the Flicker Pst and Plt timers Click OK to exit the Flicker screen Click Help for more information on this topic Instantaneous Readings Refer to the Instantaneous section of the Main screen above If you are on the Short or Long Term screens click on the Instantaneous tab to display the Instantaneous screen The PU values Pinst for Voltage Inputs Va Vb and Vc are displayed here and are continuously updated The corresponding Current Voltage values for each channel are displayed for reference G Electro Industries GaugeTech Doc E107706 V1 25 12 5 E Short Term Readings Click on the Short Term tab to access the screen containing three groups of Pst readings Pst Readings Displayed e Current Pst values for Va Vb and Vc and the time of computation e Current Pst Max values for Va Vb and Vc since the last reset and the time of the last reset e Current Pst Min values for Va Vb and Vc since the last reset and the time of the last reset The following screen is displayed Time Volts A 07 22 2003 09 48 00 23 Current Next FST II Next PLT EEE Volts C Max Volts A Volts B 07 22 2003 09 48 00 23 07 22 2003 09 48 00 23 Status 00 02 2000 01 47 00 17 00 14 2000 04 33 00 06 Max Yolts C 00 14 2000 02 00 00 07 Frequency Base Min Volts A Current 2 Min Yolts B 00 02 2000 01 42 00 09 00 02 2000 01 42 00 09 mi KA EA KK
135. sk 255 255 255 0 Example Default Gateway 0 0 0 0 Example Computer Name NETWORK Example Baud Rate 115200 Example NOTE DO NOT check Obtain IP Address using DHCP Server if you have an IP Address After the above parameters are set Communicator EXT will connect via the network using a Device Address of 1 and the assigned IP Address using the following steps 1 Double click on Communicator EXT icon to open 2 Click the Connect icon in the icon tool bar The Connect screen will appear 3 Click the Network button at the top of the screen The screen will change to one requesting the following information Device Address 1 Host IP Address per your network adminitrator Example 10 0 0 1 Network Port 502 Protocol Modbus TCP 4 Click the Connect button at the bottom of the screen Communicator EXT connects to the Nexus with the Host IP Address via the Network To connect with other Nexus Meters in either local or remote locations you MUST use the Ethernet Gateway as a Master and an RS 485 connection to any port on the remote Nexus The Address of the remote Nexus MUST be something other than 1 1 is reserved for the Nexus connected to the network via its RJ 45 The link using RS 485 is viable for up to 4000 feet 1219 meters Electro Industries GaugeTech Doc E107706 V1 25 11 3 G Electro Industries GaugeTech Doc E107706 V1 25 Chapter 12 Flicker 12 1 Overview Flicker is the sensat
136. sulting energy that would be transmitted as a result of the illustrated power values For this illustration it is assumed that the power level is held constant for each minute when a measurement is taken Each bar in the graph will represent the power load for the one minute increment of time In real life the power value moves almost constantly BE The data from Figure 1 7 is reproduced in Table 2 to illustrate the calculation of energy Since the time increment of the measurement is one minute and since we specified that the load is constant over that minute we can convert the power reading to an equivalent consumed energy reading by multiplying the power reading times 1 60 converting the time base from minutes to hours Time minutes gt Figure 1 7 Power Use Over Time G Electro Industries GaugeTech Doc E107706 V1 25 1 6 SCHER E A jo we ee ee Table 1 2 Power and Energy Relationship Over Time 3 5 4 5 5 5 JL JJ 0 0 0 5 70 70 70 0 0 70 As in Table 1 2 the accumulated energy for the power load profile of Figure 1 7 is 14 92 kWh M Demand is also a time based value The demand is the average rate of energy use over time The actual label for demand is kilowatt hours hour but this is normally reduced to kilowatts This makes 1t easy to confuse demand with power But demand is not an instantaneous value To calculate demand it is necessary to accumulate the energy readings as illustrated in
137. t Button lt lt lt lt lt 9 6 9 5 Analog Transducer Signal Output Modules lt 9 7 OD IA e eet MAS we Bite ok the A AS ADD ee ho AA hs A 9 7 952 Normal Mode EE nos Be bo j mit amp dele Se boa n de 4 9 8 9 6 Analog Input Modules lt lt lt 9 9 OO OVERVIEW E Gece es a sako at aaia Se ds EE eh hat ee gt sy v 9 9 96 2 Normal Mode s eea and da eet e PCA Ra der im Se Eee tt SE 9 10 9 7 Digital Dry Contact Relay Output Form C Module 9 11 OCT Vs OV TVI W e So See a a diet a ON a ane de 9 11 9 7 2 Communication lt lt lt EA 9 12 9 73 Normal Modesti lt er weert Ree wh onu dc e eg te B atd dy yb dec ah eh 9 12 9 8 Digital Solid State Pulse Output KYZ Module 9 13 9 8 1 OvervieW 5 224 48 De ee te A k JE dd he Pe Boch Le 9 13 9 8 2 Communication lt lt lt 9 14 9 8 35 Normal Mod er Rief oe Gal a u Du ar oby ma un Glee Ge 9 14 9 9 Digital Status Input Module lt lt lt 9 15 DO Overview a G huit re Ga 9 a 9 15 99 25 COMMUNICALION e td a la us ele ko i a vd lg al 9 15 9 9 3 Normal Mode E Aa et l ake HA a dat Auf Len 9 16 9 10 Specifications lt lt lt lt lt lt lt 4 4 e
138. t least the following information Manufacturer Unit Serial Number Transformer MVA Rating Self Cooled Test Voltage No Load Loss Watts Load Loss Watts or Full Load Loss Watts Exciting Current 100 voltage Impedance BE The transformer MVA rating is generally the lowest MVA rating the self cooled or OA rating of the transformer winding The test voltage is generally the nominal voltage of the secondary or low voltage winding For three phase transformers these values will typically be the three phase rating and the phase to phase voltage All of the test measurements are based on these two numbers Part of the process of calculating the loss compensation percentages is converting the transformer loss values based on the transformer ratings to the base used by the meter M Correct calculation of loss compensation also requires knowledge of the meter installation In order to calculate the loss compensation settings you will need the following information regarding the meter and the installation e Number of meter elements Potential Transformer Ratio PTR Current Transformer Ratio CTR Meter Base Voltage Meter Base Current M This section is limited to application of Nexus meters to three element metering installations As a result we know that e Number of metering elements 3 e Meter Base Voltage 120 Volts e Meter Base Current 5 amps M The loss compensation values can be calculated by clicking the TLC Calcula
139. ter 04100 or registers 04103 04112 or registers 04109 04112 These writes can be interpreted as two byte four byte six byte or eight byte energy readings The reception of the first value for a given channel provides the initial value for that channel Subsequent writes will increment the Residual for that channel by the difference of the old value and the new value The previous value is then replaced with the new value Attempting to write a value greater than the programmed Rollover Value for a given channel is completely ignored and no registers are modified If the difference is greater than half of the programmed Rollover Value for a given channel the write does not increment the Residual but does update the Last Value Overflow of the Residual is not prevented 2 The second process occurs in the main loop and attempts to decrement the Residual by the Programmed Energy Pulse Value If the Residual is greater than the Programmed Energy Pulse Value and the Pending Pulses Value for that channel is not maxed then Residual is decremented appropriately and the Pending Pulses is incremented by two signifying two more transitions and one more pulse 3 The third process runs from a timer which counts off pulse widths from the Programmable Minimum Pulse Width Values If there are Pulses Pending for a channel and the delay has passed then the Pulses Pending is decremented for that channel and the Output Relay is toggled M Operation Indicator 0000
140. tering may also exist when the ownership changes several miles along a transmission line where it is simply impractical to install metering equipment Ownership may change at the midway point of a transmission line where there are no substation facilities In this case power metering must again be compensated This condition is shown in Figure 7 2 Point of Ownership Change Figure 7 2 Joint Ownership Line Metering Requiring Loss Compensation G Electro Industries GaugeTech Doc E107706 V1 25 7 1 A single meter cannot measure the losses in a transformer or transmission line directly It can however include computational corrections to calculate the losses and add or subtract those losses to the power flow measured at the meter location This is the method used for loss compensation in the Nexus meter The computational corrections used for transformer and transmission line loss compensation are similar Generically no load losses and full load losses are evaluated and a correction factor for each loss level is calculated However the calculation of the correction factors that must be programmed into the meter differ for the two different applications For this reason the two methodologies will be treated separately in this chapter In the Nexus meter Loss Compensation is a technique that computationally accounts for active and reactive power losses The meter calculations are based on the formulas below These equations describe the am
141. tion method the meter has been designed for this application Line loss compensation is calculated in the meter using the same terms but the percent values are calculated by a different methodology as described in a subsequent section below Nexus 1250 1252 Transformer Loss Compensation e Performs calculations on each phase of the meter for every measurement taken Unbalanced loads are accurately handled e Calculates numerically eliminating the environmental affects that cause inaccuracies in electromechanical compensators Electro Industries GaugeTech Doc E107706 V1 25 7 2 e Performs Bidirectional Loss Compensation e Requires no additional wiring the compensation occurs internally e Imposes no additional electrical burden when performing Loss Compensation E Loss Compensation is applied to 1 second per phase Watt VAR readings and because of that affects all subsequent readings based on 1 second per phase Watt VAR readings This method results in loss compensation be applied to the following quantities e Total Power e Demands per phase and Total Thermal Block Fixed Window Rolling Sliding Window and Predictive Window e Maximum and Minimum Demands e Energy Accumulations e KYZ Output of Energy Accumulations NOTE Loss Compensation is disabled when the meter is placed in Test Mode 7 2 Nexus 1250 1252 Transformer Loss Compensation M The Nexus meter provides compensation for active and reactive power quantities
142. tor button on the Transformer Loss screen of the Nexus Device Profile MS Excel Spreadsheet or by completing the worksheet Three Element Loss Compensation Worksheet below In order to activate the Excel Spreadsheet you must have MS Excel installed on your computer NOTE A copy of the Excel Spreadsheet with Example Numbers can be found in Appendix A of this manual G Electro Industries GaugeTech Doc E107706 V1 25 7 4 7 2 1 1 Three Element Loss Compensation Worksheet E Transformer Data from Transformer Manufacturer s Test Sheet O a waw PE SE wrew Y Value bee Y Enter 3 Phase or 1 Phase values If 3 Phase values are entered calculate 1 Phase values by dividing 3 Phase values by three Convert 1 Phase Loss Watts to 1 Phase kW by dividing 1 Phase Loss Watts by 1000 Value 3 Phase MVA 1 Phase MVA 1 Phase kVA Enter 3 Phase or 1 Phase values If 3 Phase values are entered calculate 1 Phase values by dividing 3 Phase values by three Convert 1 Phase Self Cooled MVA to 1 Phase kVA by multiplying by 1000 Exciting Current Impedance Value Phase to Phase Phase to Neutral Full Load Current Amps Test Voltage is generally Phase to Phase for three phase transformers Calculate Phase to Neutral Voltage by dividing Phase to Phase Voltage by V3 Calculate Full Load Current by dividing the 1 Phase kW Self Cooled Rating by the Phase to Neutral Voltage and multiplying by 1000 G Electro Industries GaugeT
143. ud rate for 30 seconds This will enable you to interrogate the I O using the Communicator EXT software see the Modbus Communicating I O Modules User Manual Model Module Factory Set Address ImAON4 0 1mA 4 Channel Analog Output 128 1mAON8 0 1mA 8 Channel Analog Output 128 20mAON4 4 20mA 4 Channel Analog Output 132 20mAON8 4 20mA 8 Channel Analog Output 132 8AI1 0 1mA 8 Channel Analog Input 136 8AI2 0 20mA 8 Channel Analog Input 140 8AI3 0 5V je 8 Channel Analog Input 144 8AI4 0 10V de 8 Channel Analog Input 148 4RO1 4 Latching Relay Outputs 156 4PO1 4 KYZ Pulse Outputs 160 8DI1 8 Digital Status Inputs Wet Dry 164 G Electro Industries GaugeTech Doc E107706 V1 25 9 6 9 5 Analog Transducer Signal Output Modules Analog Transducer Signal Output Modules Specifications 1mAON4 4 Channel Analog Output O 1mA ImAONB 8 Channel Analog Output O 1mA Model Numbers 20mAON4 4 Channel Analog Output 4 20mA 20mAON8 8 Channel Analog Output 4 20mA RS 485 Modbus RTU Programmable Baud Rates 4800 9600 19200 57500 15 20V q at 50 200mA Power Requirement Nexus 1250 1252 Unit supports up to 2 Modules Operating Temperature 20 to 79 C 4 to 158 F Maximum Load Impedance 0 1mA 10k Q 4 20mA 500 Q Modbus Address 1mAON4 0 1mA 128 ImAON8 0 1mA 128 20mAON4 4 20mA 132 20mAON8 4 20mA 132 Baud Rate 57600 Transmit Delay Time 0 Modbus Address 247 Communication Factory Settings Default Settings
144. urs A type of LAN network connection that connects two or more devices on a common communications backbone An Ethernet LAN consists of at least one hub device the network backbone with multiple devices connected to it in a star configuration The most common versions of Ethernet in use are 10BaseT and 100BaseT as defined in IEE standards However several other versions of Ethernet are also available Error Code Modbus communication transmitted in a packet from the Slave to the Master 1f the Slave has encountered an invalid command or other problem Glossar y 2 Flicker Form Harmonics Heartbeat Pulse Infrared Test Pulse Integer Internal Modem Invalid Register ITIC Curve kWh KYZ Output LCD LED Master Device Maximum Demand Electro Industries Gauge Tech Doc E107706 V1 25 Flicker is the sensation that is experienced by the human visual system when it is subjected to changes occurring in the illumination intensity of light sources IEC 61000 4 15 and former IEC 868 describe the methods used to determine flicker severity Wiring and Hookup configuration for the Nexus 1260 1270 Measuring values of the fundamental current and voltage and percent of the fundamental Energy indicator on the face of the Nexus 1250 1252 pulses are generated per the programmed K value Energy indicator located on the upper left side of the face of the Nexus 1260 1270 meter pulses are generated p
145. use the Stand Alone Interface Cable provided with the display The cable is six 6 feet long with 20 AWG conductors see detail below Insert one end of the supplied cable into Port 3 of the Nexus 1250 1252 Meter Port 3 is factory set to match the Nexus Display s baud rate of 9600 To use a port other than Port 3 you must set the port s baud rate to 9600 using the Communicator EXT software see the Communicator EXT User Manual Insert the other end of the cable into the back of the Nexus P60N Display The connectors fit only one way into the ports Nexus P60N Display Port Nexus P60N Display Back View Detail Stand Alone Interface Cable 5 4 3 2 1 Top j aaa CONTRAST Silver RS 232 O Red Ze Twisted White air rs she Dei 9 PWR DE9 GND5 O Factory Test DCIN 12 30VDC 5 Connector GND 4 485 3 485 2 GND 1 Bottom P60N Connection Color Key LCD Nexus Color Pattern 5 DCIN HA CSSS 12 80V Dc Vi neg 4 GND V Black 3 485 A White ees ee 2 485 B Black 1 GND S Silver SET A SRNA Nexus Meter Port 3 Figure 5 11 Nexus Meter Connected to Nexus P60N Touch Screen Display Electro Industries GaugeTech Doc E107706 V1 25 5 12 5 10 Communication Ports on the Nexus 1 0 Modules M Female RS 485 Side Port use to connect to another modules female RS 485 side port E Male RS 485 Side Port use to connect to the Nexus Meter s Port 4 see section 5 8 or to
146. verage is the average power calculated over a user set time interval that is derived from a specified number of sub intervals each of a specified time For example the average is calculated over a 15 minute interval by calculating the sum of the average of three consecutive 5 minute intervals This demand calculation methodology has been adopted by several utilities to prevent customer manipulation of KW demand by simply spreading peak demand across two intervals A type of serial network connection that connects two devices to enable communication between devices An RS 232 connection connects only two points Distance between devices is typically limited to fairly short runs Current standards recommend a maximum of 50 feet but some users have had success with runs up to 100 feet Communications speed is typically in the range of 1200 bits per second to 57 600 bits per second RS 232 connection can be accomplished using Port 1 of the Nexus 1250 1252 or the Optical Port on the face of the Nexus 1260 1270 A type of serial network connection that connects two or more devices to enable communication between the devices An RS 485 connection will allow multi drop communication from one to many points Distance between devices 1s typically limited to around 2 000 to 3 000 wire feet Communications speed 1s typically in the range of 120 bits per second to 115 000 bits per second A voltage quality event during which the RMS voltage is lower than normal
147. wever if you are using the Internal Modem or Network Option Port 2 is labeled Modem Ethernet Gateway Ports 1 3 and 4 DO NOT change The l O Modules MUST use Port 4 Port 3 is an alternate Nexus P40N P41N or P43N Display is shipped programmed to use Port 3 see section 5 7 for details Figure 5 4 Communication Wiring Electro Industries GaugeTech Doc E107706 V1 25 5 4 5 2 RS 232 Connection Nexus Meter to a Computer E Use Port 1 for RS 232 communication Set the selector switch beneath the port to RS 232 M Insert one end of an RS 232 extension cable into the Nexus Meter s 9 pin female serial port Insert the opposite end into a port on the computer M The RS 232 standard limits the cable length to 50 feet 15 2m M The RS 232 Port is configured as Data Communications Equipment DCE Nexus Meter Port 1 RS 232 Port RS 485 Port Pin 2 Transmit see Section 5 8 for details Pin 3 Receive Pin 5 Ground S DS V S B A Pd 9 8 7 6 Switch set for RS 232 communication M RS 232 RS 485 Figure 5 5 Nexus Port 1 RS 232 RS 485 Communication 5 3 Nexus RS 485 Wiring Fundamentals with Ry Explanation Nexus RS 485 Ports Ports 1 4 see Figure 5 5 above V Voltage terminals for power connections Use with Nexus I O Modules and the Nexus Displays only The Nexus 1250 1252 Meter supplies 17V DC through the V ter minal connections Note Do not connect these pins to devices th
148. wo parameters have been defined one for the short term called Pst defined in this section and one for the long term called Plt defined in the next section The standard measurement time for Pst is 10 minutes Pst is derived from the time at level statistics obtained from the level classifier in Block 5 of the flicker meter The following formula is used P 0 03 14P 0 0525P 0 0657P 0 28P 0 08P Where the percentiles P 0 1 PO PG POLO P 50 are the flicker levels exceeded for 0 1 1 2 20 and 50 of the time during the observation period The suffix S in the formula indicates that the smoothed value should be used The smoothed values are obtained using the following formulas P 1s P 7 P 1 P 1 5 3 P 3s P 2 2 P 3 P 4 3 P 10s P 6 P 8 P 10 P 13 P 17 5 P 50s P 30 P 50 P 80 3 The 3 second memory time constant in the flicker meter ensures that P 0 1 cannot change abruptly and no smoothing is needed for this percentile e Long Term Flicker Evaluation The 10 minute period on which the short term flicker severity is based is suitable for short duty cycle disturbances For flicker sources with long and variable duty cycles e g arc furnaces it is necessary to provide criteria for long term assessment For this purpose the long term Plt is derived from the short term values over an appropriate period By definition this is 12 short term values of 10 minutes
149. xus Monitors A Daisy Chain can include up to 31 meters If more are desired the installation of a repeater allows additional meters See section 5 14 for repeater details RS 485 Originate Modem or Internal to PC Figure 10 1 Nexus with Internal Modem Option G Electro Industries GaugeTech Doc E107706 V1 25 10 1 10 2 Hardware Connection BE Use RJ 11 Standard Telephone Line to connect with an INP2 Option Nexus The RJ 11 line is inserted into the RJ 11 Port on the face of the Nexus 1250 1252 with Internal Modem Option The connection using RJ 11 into the Nexus is virtually unlimited since it utilizes a PSTN Public Switched Telephone Network To connect with other Nexus 1250 1252 Monitors in either local or remote locations you MUST use Port 2 as a Master and an RS 485 connection to any port on the remote Nexus The Address of the remote Nexus MUST be something other than 1 The link using RS 485 is viable for up to 4000 feet 1219 meters 10 3 Dial In Function IE The modem continuously monitors the telephone line to detect an incoming call When an incoming call is detected the modem will wait a user set number of rings and answer the call The modem can be programmed to check passwords and lock out unsuccessful attempts to connect When an incoming call is successfully connected the control of communications is passed to the calling software program The modem will respond to computer demands

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