- 1 - User`s Manual: Series 270I Model 270I Process Current Loop
Contents
1. 1 1 NOTE PLASTIC ENCLOSURE SNAPS TOGETHER AT SEAMS 0 984 9 45 25 9 11 43 2 2 WIRE INSERTION LOCATION 2 PLACES t 9 RAIL DIN MOUNTING RAIL DIN MOUNTING SHOWN THIS SIDE SHOWN THIS SIDE 3 3 DIN EN 50035 32mm DIN EN 50022 35mm RAIL DIN MOUNTING SHOWN HERE DIN 50035 32mm RAIL DIN MOUNTING SHOWN HERE Sii DIN EN 50022 35mm 6 79 0 4 1 55 1 55 4 39 4 39 4 SCREWDRIVER SLOT FOR REMOVAL FROM RAIL NOTE ADJACENT UNITS CAN BE MOUNTED ON 1 0 INCH 25 4mm CENTERS 3 35 5 5 85 09 3 55 90 17 DIN RAIL MOUNTING DIN OPTION meron wen PRR NOTE ALL DIMENSIONS ARE IN INCHES MILLIMETERS HOUSING DIN RAIL MOUNT 5 7 2701 1 4501 107 NOTE PLASTIC ENCLOSURE SNAPS TOGETHER AT SEAMS WIRE INSERTION LOCATION 2 PLACES 3 11 79 0 3 90 99 08 2 89 3 73 41 3 18 78 75 MTG SLOTS 0 148 3 756 WIDE TO CLEAR 6 SCREWS 2 PLACES 25 0 INE ENCLOSURE DIMENSIONS SURFACE MOUNTING 5 OPTION NOTE ALL DIMENSIONS ARE IN INCHES MILLIMETERS G NOTE PLASTIC ENCLOSURE SNAPS TOGETHER AT SEAMS 0 98 2 49 SCREWDRIVER SLOT FOR REMOVAL WIRE INSERTION 0 70 LOCATION 2 PLACES 17 78 14 22 ie 12. 3 20 81 28 9 Gea a 6 85 5 30 83 82 3 80 96 52 NOTE 1 PLASTIC RAIL ENCLOSURE DIMENSIONS 1220F 8090 SNAPTRACK MOUNTING ST OPTION Acromag 28 91 8 AUG 98 HOUSING SM 5 OPTION OE BE GROUND WIRE CONNECTION SERIES 2701 ISOLATOR SHOWN IN ENCLOSURE WITH COVER OPEN NOTE ROOM IS AVAILABLE FOR A SECOND UNIT WITH THE SM SURFACE MOUNT OPTION ORDER SEPARATELY NOTE ALL DIMENSIONS ARE IN INCHES MILLIMETERS __ 2 gt ____ 7 50 190 5 9 375 9 5 1 NOTES 1 THESE SPECIFIC CLAMPS ON NEMA 4 ENCLOSURES ONLY CONDUIT MOUNTING HOLES AND FITTINGS ARE CUSTOMER SUPPLIED 8 313 7 9 DIA HOLE 4 PLACES 3 4 4 amp 12 OPTION 8 ENCLOSURE DIMENSIONS MICH mE ENCLOSURE 4 amp 12 OPTION ofr 272 __ 1 4501 109 01 O RING GASKET MOUNTING SCREWS 2 PLACES 6 52 THD 0 25 INCH SERIES 2701 ISOLATOR SHOWN INSTALLED IN ENCLOSURE WITH COVER REMOVED SERIES 2701 ISOLATOR SERIES 2791 ISOLATOR SHOWN REMOVED FROM ENCLOSURE NOTE ALL DIMENSIONS ARE INCHES MILLIMETERS 4 60 116 84 1 90 25 4 0 8 20 32 ENCLOSURE DIMENSIONS OPTI
3. Input Connect input per connection diagram Observe proper polarity Note Input Output circuits are isolated from each other allowing the output circuit to operate with common mode voltages up to 250V AC or 354V DC off ground on a continuous basis The power to operate this loop isolator is derived from the input signal For a 250 ohm load the input voltage drop with 20mA output is 10 8VDC 5 4VDC 0 0216 x R load Determine the input voltage requirements for your load Make sure your input source is capable of handling the required voltage drop 2 Output Make output circuit connections to the loop isolator as shown in the Connection Drawing 4501 106 The 4 20mA DC output signal can be used with a resistor load from 0 to 600 ohms For resistance loads from 50 to 600 ohms connect R load between the Output and Output terminals For resistance loads from 0 to 50 ohms connect R load between the Output S and Output terminals The Output S terminal has a built in padding resistor of 50 ohms 3 Grounding The isolator in the General Purpose Housing is plastic and does not require an earth ground connection If the isolator is mounted in a metal housing a ground wire connection is required Connect the ground terminal Green Screw to a suitable earth ground using suitable wire per applicable codes CALIBRATION All units are calibrated and checked for proper performance at the factory before they are shipped The calibr
4. complete assembly DIN General Purpose Housing DIN Rail Mount amp rails Rail 832mm Type 50035 Rail 35mm Type EN50022 Refer to Drawing 4501 107 for outline and clearance dimensions Shipping Weight 1 pound 0 45 Kg packed SM General Purpose Housing Surface Mount Refer to Drawing 4501 108 for outline and clearance dimensions Shipping Weight 1 pound 0 45 Kg packed ST General Purpose Housing SNAPTRACK Refer to Drawing 4501 108 for outline and clearance dimensions Shipping Weight 1 pound 0 45 Kg packed SNAPTRACK is a registered trademark of Reed Devices Inc NEMA 4 and 12 Enclosures Option types listed below Refer to Drawing 4501 109 for outline and clearance dimensions Isolator is mounted within enclosure at the factory These enclosures may accommodate a second Series 270 isolator with the Surface Mount option SM option ordered separately Conduit mounting holes and fittings are customer supplied N4 Water Tight Enclosure NEMA 4 Enclosure material and finish 0 075 and 0 060 inch thick steel with gray hammertone enamel finish inside and out Shipping weight 6 pounds 2 7 Kg packed N12 Oil Tight Enclosure NEMA 12 Enclosure material and finish 0 075 and 0 060 inch thick steel with gray hammertone enamel finish inside and out Shipping weight 6 pounds 2 7 Kg packed Explosion Proof Water Tight Enclosures Option type listed below Refer to Drawing
5. test signal of 40 to 200mV that is directly proportional to the 4 to 20mA input signal The only penalty is the increased fixed voltage drop that results 200mV Again the use of this resistor is optional These field mounted loop powered isolators are designed to utilize one of a number of customer specified mounting configurations The isolator is available for DIN rail mounting surface mounting 3 inch plastic mounting or in various housings These housings include NEMA 4 12 and explosion proof enclosures The model number of the unit specifies the mounting enclosure type refer to Table 1 Input wiring is inserted in the top of the unit while output wiring is inserted in the bottom or field side of the unit Screws to secure the wiring are located on the front panel Connectors are screw clamp type and accept wire size up to 14 AWG SPECIFICATIONS Function This loop powered isolator accepts a 4 to 20mA input signal provides input to output circuit isolation and produces a 4 to 20mA output for loads from 0 to 600 ohms Zero and span trim adjustments utilize 22 turn potentiometers accessible from the front of the unit The isolator has various mounting and enclosure options available MODEL SERIES 270l Color coded with Red label INPUT 20MA 4 to 20mA input Power to operate the loop isolator is derived from the input signal loop Input current should be limited to less than 50mA to
6. 4501 110 no display window for outline and clearance dimensions Enclosure Materials Body and cover Copper free aluminum less than 0 4 Gasket Neoprene Finish Corro free epoxy powder coat color gray Hub size 0 75 inch Quantity 2 Housing meets Class Groups amp D Class Groups amp Class III and NEMA 4 water tight requirements Isolator is mounted within enclosure at the factory XP Explosion Proof Water Tight Enclosure No Window Shipping weight 5 pounds 2 3Kg packed CERTIFICATION Consult the factory for current information on the availability of agency e g Canadian Standards Association Factory Mutual etc approvals NCR No Certification Required INSTALLATION The isolator is packaged in a general purpose plastic housing and optionally mounted within a variety of protective enclosures The isolator should be located in an area that is protected from dust moisture and corrosive atmospheres The enclosure type determines the protection afforded in a particular environment and location make sure that this is not compromised Maximum operating ambient temperatures should be within 13 to 185 F 25 C to 85 C for satisfactory performance If unit is factory calibrated it is ready for installation Connect as shown in Connection Drawing 4501 106 To verify calibration refer to the CALIBRATION section Mounting Mount isolator assembly refer to appropriate
7. USA Data and specifications are subject to change without notice 8500 288 B94C002 INTRODUCTION These instructions cover the model types listed in Table 1 below Supplementary sheets are attached for units with special options or features Table 1 A Model Number Format 2701 Input Mounting Certification B Typical Model Number 270I 20MA DIN NCR Series Certification Mounting Notes Table 1 1 All units are factory calibrated for 4 to 20mA no C needed 2 Consult the factory for current information on agency e g Canadian Standards Association etc approvals DESCRIPTION This two wire loop powered isolator accepts a 4 to 20mA input signal and provides an isolated 4 to 20mA output signal It is designed to break the galvanic path between a transmitted signal source and the receiving device The isolator is highly effective in eliminating unreliable or inaccurate signal transfer by providing total current to current signal isolation The isolator is RFl protected operates over a wide temperature range and features excellent temperature coefficients which minimize the effects from harsh plant environments See Drawing 4501 105 for a simplified schematic Key 270 Features Transformer Isolation No Load Trimming Required Signal Loop Wide Temperature Range Powered 0 600Q Load Range Input Current Sense Resistor Accuracy Versatile Moun
8. for one minute without breakdown This complies with the test requirements outlined in ANSI ISA 582 01 1988 for the voltage rating specified Output 4 20mA DC output into 0 to 600 ohms A For R load from 50 to 600 ohms Connect R load between the Output and Output terminals B For R load from 0 to 50 ohms Connect R load between the Output S and Output terminals For optimum performance at low values of R load the isolator has a built in pad resistor of 50 ohms 1 Input Voltage Drop with the input sense resistor not used Input Voltage Drop 5 4VDC 0 0216A x R load 50Q 2 Input Voltage Drop with the input sense resistor used Input Voltage Drop 5 6VDC 0 0216 x R load 50Q Reference Test Conditions Input Output current 4 to 20mA output load 250 ohms 77 F 25 C ambient Accuracy Better than 0 1 of output span This error includes the combined effects of isolator repeatability hysteresis terminal point linearity and adjustment resolution Ambient Temperature Range 13 F to 185 F 25 C to 85 C Ambient Temperature Effect Less than 0 006 of output span per 0 01 per C over the ambient temperature range for reference test conditions Specification includes the combined effects of zero and span over temperature Load Resistance Effect Less than 0 1 of output span as load resistance is changed over entire range Allows use of isolator within resistance load rang
9. outline drawing for mounting and clearance dimensions Determine which configuration is utilized and consult the proper mounting instructions listed below 1 DIN Rail Mounting Use suitable fastening hardware to secure the DIN rail to the designated mounting surface An isolator ordered with the DIN Rail mounting option DIN can be mounted to either the Rail Installation of the isolator to the rail depends on the type of DIN rail used see Drawing 4501 107 Units can be mounted side by side on 1 0 inch centers if required 2 Surface Mounting Secure the isolator to the designated mounting surface using two 6 32 screws Note that the mounting bracket has screw slots to facilitate mounting Units can be mounted side by side on 1 0 inch centers if required Series 2701 User s Manual Isolator Process Current Loop Powered 3 SNAPTRACK Mounting Secure the SNAPTRACK mounting channel to the designated mounting surface using suitable fastening hardware To install the unit in the mounting channel place the bottom end of the mounting bracket between the rails and press the top notched end firmly until the bracket snaps into place To remove the isolator insert a screwdriver into the upper arm of the connector twist to release the unit from the track and tip the unit out Units can be mounted side by side on 1 0 inch centers if required 4 NEMA 4 amp 12 Enclosure Mounting Secure the enclosure assembl
10. Acromag User s Manual Series 2701 Model 2701 Process Current Loop Powered Isolator Table of Contents Page 7 Aa neva eases Rea eee eras Description Specifications Installation Calibration General List of Drawings Page Electrical Connections 4501 106 Calibration Connection amp Simplified Schematic 4501 105 Dimensions DIN Rail Mounting 4501 107 Dimensions Surface amp Snaptrack Mtg 4501 108 NEMA 4 8 12 Enclosures 4501 109 ave Explosion Proof Enclosure 4501 110 IMPORTANT SAFETY CONSIDERATIONS It is very important for the user to consider the possible adverse effects of power wiring component sensor or software failures in designing any type of control or monitoring system This is especially important where economic property loss or human life is involved It is important that the user employ satisfactory overall system design It is agreed between the Buyer and Acromag that this is the Buyer s responsibility Acromag Inc Tel 248 624 1541 30765 South Wixom Road FAX 248 624 9234 P O Box 437 Wixom Michigan 48393 7037 USA Copyright 1991 1994 Acromag Inc Printed in the
11. ON COVER SOLID METAL FRONT FACE O RING GASKET 9 75 NPT 19 05 2 PLACES MICK mE ENCLOSURE XP OPTION 278 1 1 4501 112 l
12. OOP ISOLATOR ADJUSTMENTS CURRENT SOURCE MUST BE CAPABLE OF SUPPLYING 19 8 DC ACROSS THE LOOP ISOLATOR PLUS 5 9 ACROSS THE INPUT MEASURING RESISTOR A TOTAL OF 15 3V RECOMMENDED CALIBRATION 5 250 OUTPUT 0 01 4 20 5 DIGIT DVM 22 Bae G H 1 PADDING TEST SIGNAL RESISTOR 40 200 4 2 2 OR gt 4 20 4 29 SUPPLY SIGNAL AND AMPLIFIER OSCILLATOR REVERSE POLARITY PROTECTION INPUT A STANDARD INCLUDES INPUT CURRENT SENSE RESISTOR SENSE RESISTOR POWER ISOLATION SIGNAL ISOLATION RECTIFIER 7 FILTER __3 1 OPTIONAL GROUND 50 600 OHMS Rig 0 50 OHMS NOTE NO LOAD TRIMMING REQUIRED WITHIN RANGE SIMPLIFIED SCHEMATIC SERIES 2701 LOOP ISOLATOR CALIBRATION CONNECTIONS mica 28 FEB gt KG KG Trev enc our TE ISOLATOR CALIBRATION CONNECTIONS 54501 1 5 H
13. ation example below is provided for reference Isolator Adjustment Procedure Connect the isolator as shown in Connection Drawing 4501 106 The input current source must be adjustable over the entire input range of the unit and settable to an accuracy of 0 05 or better for proper results The Zero and Span adjustments are accessible on the front panel of the isolator see Drawing 4501 106 for their location The screwdriver blade used to adjust the potentiometers should not be more than 0 1 inch 2 54mm wide Isolator Calibration Example MODEL 2701 20 Output 4 20 Input 4 20 1 Set input source to 4 000mA Adjust the Zero Z pot until the output reads 4 000mA DC 2 Set input source to 20 000mA Adjust the Span S pot until the output reads 20 000mA DC 3 Repeat steps 1 and 2 until the readings converge The instrument is now calibrated Several mid point values should also be checked to verify proper operation of the isolator GENERAL MAINTENANCE The isolator contains solid state components and requires no maintenance except for periodic cleaning and calibration verification When a failure is suspected a convenient method for identifying a faulty isolator is to exchange it with a known good unit It is highly recommended that a non functioning isolator be returned to Acromag for repair since Acromag used tested and burned in parts and in some cases parts that have bee
14. e without the need to recalibrate the isolator for a particular load Output Ripple Less than 0 1 of the maximum output span Bandwidth 3 dB at Hz typical Response Time For a step input the output reaches 98 of output span within 80 5 typical Series 2701 User s Manual Isolator Process Current Loop Powered Noise Rejection Common Mode Better than 11088 at 60 Hz typical RFI Resistance Less than 0 5 of output span with RFI field strengths of up to 10V meter at frequencies of 27MHz 151 2 and 467MHz EMI Resistance Less than 0 25 of output span effect with switching solenoids or commutator motors Surge Withstand Capability SWC Input Output terminations rated per ANSI IEEE C37 90 1978 Unit is tested to a standardized test waveform that is representative of surges high frequency transient electrical interference observed in actual installations Construction Basic Isolator Circuit Board Military grade FR 4 epoxy glass circuit board Circuit Board Coating Fungus resistant acrylic conformal coat Terminals Compression type wire size 14 AWG maximum Mounting Position Position insensitive Case Self extinguishing NYLON Type 6 6 polyamide black thermo plastic UL94 V 2 General Purpose NEMA Type 1 enclosure MOUNTING A wide variety of mounting options and enclosures are available to meet the needs of the installation The available models are listed below The isolator is shipped as a
15. n selected for characteristics beyond that specified by the manufacturer Further Acromag has automated test equipment that thoroughly checks the performance of each isolator CURRENT SENSE TWO WIRE CURRENT FOUR WIRE 221 TRANSMITTER SENSE TRANSMITTER 40 20 BUILT IN RESISTOR BUILT IN SEE NOTE 1 gt 10 OHMS RESISTOR NC 40 208 19 5 40 209 4 2 TYPICAL 2 WIRE TYPICAL 4 WIRE TRANSMITTER TRANSMITTER INSTALLATION INSTALLATION Ri gap 50 TO 600 OHMS Roan 0 TO 5 OHMS oad 58 600 OHMS 9 50 5 SEE NOTE 3 SEE NOTE 3 SEE NOTE 3 SEE NOTE 3 OPTIONAL OPTIONAL OPTIONAL 1 GROUND 1 GROUND GROUND NOTES 1 INPUT SENSE RESISTOR NOT USED INPUT INPUT R LOAD TO 58 OHMS INPUT VOLTAGE DROP 5 4V DC 0216A x 50 OHMS R LOAD 50 TO 600 OHMS INPUT VOLTAGE DROP 5 4V 0 0216 x R LOAD 2 INPUT SENSE RESISTOR USED INPUT S INPUT R LOAD TO 50 OHMS INPUT VOLTAGE DROP 5 6V DC 9 0216 x R LOAD 50 OHMS R LOAD 50 TO 600 OHMS INPUT VOLTAGE DROP 5 6V DC 0216A x R LOAD 3 ISOLATOR DOES NOT REQUIRE TRIMMING FOR A SPECIFIC LOAD RESISTANCE LOOP ISOLATOR CONNECTIONS Acromag 28 91 Wixom mich 5 DIGIT DVM 250 ADJUSTABLE INPUT 0 01 DC CURRENT SOURCE L
16. prevent damage to the isolator In the event of an open output circuit the input loop voltage drop is limited to 20V nominal Isolator has reverse polarity protection Input Voltage Drop The input voltage drop is a function of the input current as follows Vinput 18 36V 8500 16 20V 7500 14 04 6500 11 88V 5500 9 72V 4500 7 56 3500 5 40 2500 0 100 200 300 400 500 600 OUTPUT LOAD RESISTANCE 0 Figure 1 Input Burden vs Output Load 21 6mA Loop Current Equation Refer to Figure 1 Input Voltage Drop 5 4V DC 0 0216A x R load Example R load 250 ohms Input Voltage Drop 5 4V DC 0 0216A x 250Q 10 8V DC Current Sense Resistor A built in 10 ohm 0 1 resistor is available to monitor the input current to the isolator The wiring to the isolator s input terminals determines if this resistor is included in the current loop or not The use of this resistor provides a test signal of 40mV to 200mV representing 4 to 20mA See Drawing 4501 106 for wiring details Note that the use of this resistor will increase the Input Voltage Drop by 200 10 ohms x 20 Input V Drop 5 4VDC 0 0216A xR load no sense resistor Input V Drop 5 6VDC 0 0216A xR load w sense resistor Isolation The input and output circuits are isolated from each other for common mode voltages up to 250V AC or 354V DC off ground on a continuous basis will withstand 1500V AC dielectric strength test
17. ting Configuration Power to operate the unit is derived from the input signal current no external power supply is required When a signal isolation device is installed it is important to consider the voltage drop or additional line resistance that will be placed in the system Any additional load tends to reduce the line or drive potential and may exceed the source rating The effect of voltage drop within the system must be calculated to ensure that drive capability is not exceeded Total maximum voltage drop in the input current loop is the sum of the isolator s fixed voltage drop plus the voltage required to drive the output load The output load resistance range 15 from 0 to 600 ohms Series 2701 User s Manual Isolator Process Current Loop Powered Placing a resistor across the output terminals will provide a voltage output proportional to the loop current such as 1 to 5V DC 4 to 20mA for a 250 ohm load A unique feature of this isolator is that once it is calibrated it does not have to be recalibrated for different loads up to 600 ohms That is calibration is independant of the load The isolator is calibrated at the factory with a 250 ohm load and the need for a load trim adjustment is not required for other load values To facilitate field indication of the current going into the isolator the user has the option to wire the input to include a built in 10Q resistor 0 1 25ppm C in the current loop This provides a
18. y to the designated mounting surface using appropriate hardware The isolator is secured within this enclosure using two screws Note It is recommended that the isolator be removed from the enclosure during the process of drilling holes installing fittings and mounting the enclosure Note It is recommended that the isolator be removed from the enclosure during the process of mounting the enclosure To remove the unit from the enclosure remove two screws securing it to the bottom of the enclosure After the enclosure is installed install the isolator into the enclosure Position the unit at an angle that permits all wiring to be routed unobstructed through both ports If the isolator has the display option make sure the orientation of the display allows for easy reading once installed Secure the isolator assembly to the enclosure using two screws Electrical Connections The wire size used to connect the unit to the control system is not critical All terminal strips can accommodate wire from 14 26 AWG Strip back wire insulation 1 4 inch on each lead before installing into the terminal block Input wiring may be shielded or unshielded twisted pair Output wires should be twisted pair Since common mode voltages can exist on signal wiring adequate wire insulation should be used and proper wiring practices followed It is recommended that input wiring be separated from output signal wiring for safety as well as for low noise pickup 1
Download Pdf Manuals
Related Search