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DigitalFlow™ GM868 Service Manual 1 MB

1. 3 Nut amp Washers typ Keypad Cable LCD Display Display Shroud Standoff typ DigitalFlow GM868 Service Manual 54 A Acceleration Error E6 o ooooooo 21 Alarms Option Card Testing oooo 11 Amplitude Error E3105 v 34 ad idea 21 Analog Inputs Option Card Calibrating 6 Analog Output Error E7 aasaaaaenaena nan 21 Analog Outputs Slot 0 As Calibrated Current Source o oooooooo o 6 Calibrating ue aa pasan 2 Enciso is ente oS 2 Resolution Li ee vae e ew RR Ra 2 Analog Outputs Option Card Calibrating sende bed sirno cea SI m ase isa 2 Linearity e ea iere d Certe a ae 2 Resolutions E AO Ge 2 B Bracket Option Card cias aaa 35 C Cable Backlight a eee aia etr a a eee eed ee s 33 37 Display er atte Re wa e REN RP RR 33 36 Keyp d g icem Civ dd ad ced ce tu ida 33 Calibrating See Parameter Name Calibration Menu Entering o o ooo o 1 Circuit Board See Printed Circuit Board Contamination Gas 28 Corrosion Transducers ooooo ooo 29 D Diagnostic Parameters Table 26 Diagnostics Menu ENEE ied di AA 4 25 a ees aaa iad A 27 Display A caret Suo te Stie ude Ae a be 33 LCIDz ceo Sih Bk E E EO ER SI 3 R placing urnas pda RARE III 36 Display Screen Error MESS ts AS 19 AAA A ai iad al 3 19 DigitalFlow GM868 Service Manual Index E EPROM Replacing iis o Aa p UR E ann e
2. 2 Using a chip puller remove the EPROM from its socket If a chip puller is unavailable a straightened paper clip may be used in the notches at opposite corners of the socket Gently pry the EPROM up a little at a time at each notch until it comes free CAUTION The EPROM is easily damaged by static electricity Before handling the new chip touch a grounded metal object to discharge any built up static electricity and avoid touching the leads on the side of the chip 3 Make sure that the beveled corner on the new EPROM is aligned with the beveled corner of the socket and place the EPROM into the socket 4 By applying equal pressure on all four corners gently press the EPROM into the socket until it is fully seated Do not strike the EPROM or apply excessive force during this procedure 5 After checking for any loose hardware that may have fallen into the enclosure reinstall the top panel on the meter and secure the panel in place with the four screws previously removed The Model GM868 flowmeter may now be placed back into service Reconnect the main power and resume taking measurements Note Be sure to record the EPROM replacement in Appendix A Service Record 48 DigitalFlow GM868 Service Manual Appendix B Optional Enclosures B 6 Rack Mount LCD Display Replacement The Model GM868 measurements are displayed on a two pane LCD graphic display panel The LCD display normally provides years of dependable service bu
3. Markings appear on the instrument label which identifies the product model serial number operating ranges hazardous area ratings entry thread type and warning and caution information EU EEA Installation Compliance The use of this apparatus is subjectto the EU directive on minimum requirements for improving the safety and health protection of workers potentially at risk from explosive atmospheres Council Directive 1999 92 EC The installer is required to be familiar with this document or the National transposing legislation Increased Safety Wiring Connections Power Connection Maximum Size Solid 4 0 mm 12 AWG Stranded 2 5 mm 14 AWG Number of conductors 2 Solid max 1 5mm 16 AWG Stranded max 1 0 mm 18 AWG All Other Screw Terminal Connections Maximum Size Solid 4 0 mm 12 AWG Stranded 2 5 mm 14 AWG Number of conductors 2 Solid max 1 5mm 16 AWG 2 Stranded max 1 0 mm 18 AWG f Single conductor Multi conductors of same cross section CSS 0013 Rev A 2 of 2 SE EC DECLARATION Sensing OF CONFORMITY DOC 0013 Rev B We GE Sensing 1100 Technology Park Drive Billerica MA 01821 USA declare under our sole responsibility that the DigitalFlow DF8688 Liquid Ultrasonic Flowmeter DigitalFlow GC868 Clamp On Gas Ultrasonic Flowmeter DigitalFlow GF868 Flare Gas Mass Ultrasonic Flowmeter DigitalFlow GM868 General Purpose Gas Ultrasonic Flowmeter Dig
4. See Part Name Return Policy ooooooooooooooo o o 57 S Screen Messages Table ooo oo 23 Service Record o ooooooooooooooooo 43 Shroud Aluminum 0 0 20 00 cece eee eee 31 37 ECD Display geo e e Ad 36 EN Doi a A eR 38 Plis MP CX E 38 Signal Quality Error E4 o ooooooooo 21 Sockets Option Card o o ooooooooooooooo o 35 Soundspeed Error Elda a Pb vn V s 20 Gas oie A REPEAT OE 28 Spare Parte Dist ius Gove ve hex ale 39 Special Input Error El0 22 56 7 Temperature Input Error E8 o 21 Totalizer Frequency Option Card Testing 13 Totals Overflow Error El4 o o o oooooo 22 Transducers WOMOSION 2 5 EA 29 Internal Damage 4 2 25624424 Sia na la 29 OAKS AS ad Padel 29 Physical Damage ss ioa soe eerte 29 Placement 242 2 marea eX VES CERE AY Ns 29 Problems eec exer E Y RA Reda 29 U User Program EPROM iaca sated aed EXER EX REA 9 34 Uporadinps us ada ias da t da 34 V Velocity Range Error E3 atrae 20 W Warranty s ene a at 57 DigitalFlow GM868 Service Manual Warranty Warranty Each instrument manufactured by GE Sensing is warranted to be free from defects in material and workmanship Liability under this warranty is limited to restoring the instrument to normal operation or replacing the instrument at the sole discretion of GE Sensing Fuses and batteries are specifically excluded from any liability This warr
5. for both 4 20 mA and 0 20 mA scales Refer to this table to verify the accuracy of the ammeter readings taken above 4 DigitalFlow GM868 Service Manual Chapter 1 Calibration 1 4 3 Testing the Analog Output Linearity cont Table 1 Expected Ammeter Readings Full Scale 4 20 mA Scale 0 20 mA Scale All ammeter readings should be 0 005 mA If the linearity test readings are not within 5 pA of the values listed in Table 1 above check the accuracy and wiring of the ammeter Then repeat the low and high end calibrations If the analog output still does not pass the linearity test contact the factory for assistance Procedure Options You have completed calibration of the analog output Do one of the following To calibrate or test another output press F4 EXIT and return to Step 3 in Accessing the Calibration Menu on page 4 To calibrate test additional slots press F4 EXIT twice and proceed to the appropriate section To leave the Calibration Menu press F4 EXIT three times DigitalFlow GM868 Service Manual 5 Chapter 1 Calibration 1 5 Calibrating the Analog Inputs Analog inputs may be added to the Model GM868 flowmeter by installing an Analog Inputs Option Card in one or more of the six expansion slots The option card contains two analog inputs which are designated as A and B Each of the inputs which may be either a 0 4 20 mA input or an RTD in
6. E mail sensing ge com Ireland Sensing House Shannon Free Zone East Shannon County Clare Ireland Tel 353 0 61 470200 E mail gesensingsnnservices ge com An ISO 9001 2008 Certified Company www ge mcs com en about us quality html www ge mcs com 2015 General Electric Company All rights reserved Technical content subject to change without notice 910 1935 Rev F
7. Manual for instructions on properly setting up the meter for accurate flow rate measurements Note Be sure to enter a complete and detailed account of the service procedure performed on the Model GM868 in Appendix A Service Record 38 DigitalFlow GM868 Service Manual Chapter 4 Parts Replacement 4 8 Spare Parts All of the necessary components to upgrade or repair the Model GM868 flowmeter are readily available from the factory As a convenient reference some of the more common spare parts are listed in Table 5 below Table 5 Spare Parts List part Number 703 1127 02 Option Card Alarms Hermetically Sealed 703 1127 03 Option Card Alarms General Purpose 703 1145 02 Option Card Analog Inputs 703 1126 02 Option Card Analog Outputs 703 1145 03 Option Card RTD Inputs 703 1144 02 Option Card Totalizer Frequency Outputs 703 1358 Option Card MODBUS 421 703 417 027 Card Cage Metal Bracket Card Guide Nylon 703 1247 Printed Circuit Board 705 671 LCD Display Assembly 147 744 EPROM 421 700 Conduit Plate 1 2 421 701 421 702 Conduit Plate 3 4 Conduit Plate Blank 421 946 LVD Plastic Shroud 421 686 Main Aluminum Shroud 442 484 Label Wiring Diagram To purchase the parts listed in Table 5 above or any items not listed in the table contact the factory for assistance To make sure the
8. Minor damage may be repaired by carefully bending the connector back into shape If the connector can not be repaired the transducers must be replaced Note Transducers must be replaced in pairs Refer to Chapter 2 Initial Setup of the Startup Guide to program the replacement transducer data into the meter If the instructions in this section fail to resolve the problem contact the factory for assistance DigitalFlow GM868 Service Manual 29 Chapter 3 Diagnostics no content intended for this page 30 DigitalFlow GM868 Service Manual Chapter 4 Parts Replacement Chapter 4 Parts Replacement 4 1 Introduction The electronics console of the Model GM868 has been designed to permit easy on site upgrades and parts replacement See Figure 8 on page 41 and Figure 9 on page 42 for details of the standard GM868 electronics console assembly The instructions in this chapter along with a few common tools are all that is required to perform the following tasks e fuse replacement printed circuit board PCB removal and installation e EPROM replacement option card installation LCD display replacement IMPORTANT For meters supplied in any of the optional enclosure types see Appendix B Optional Enclosures for instructions specific to that unit WARNING Prior to performing any maintenance procedures be sure to disconnect the main power from the unit Note For compliance with the European Union 5 Low Voltag
9. See the Programming Manual for details Refer to Chapter 3 Diagnostics to correct any flowcell and or transducer problems DigitalFlow GM868 Service Manual Chapter 2 Error Codes and Screen Messages 2 6 E4 Problem Cause Action Signal Quality The signal quality is outside the limits programmed in the SETUP submenu of the User Program Too high a signal strength may be caused by the failure of an electronic component Too low a signal strength may be caused by a flowcell or electrical problem Check for sources of electrical interference and verify the integrity of the electronics console by temporarily substituting a test flowcell that is known to be good Check the transducers and relocate them if necessary See Chapter 3 Diagnostics for instructions 2 7 E5 Amplitude Error Problem Cause Action 2 8 E6 Problem Cause Action The signal amplitude exceeds the limits programmed in the SETUP submenu of the User Program Excessive levels of an attenuating gas such as CO are present in the flowcell Solid or liquid particulates may be present in the flowcell Refer to Chapter 3 Diagnostics to correct any flowcell problems Cycle Skip Accel The acceleration exceeds the limits programmed in the SETUP submenu of the User Program This condition is usually caused by poor flow conditions or improper transducer spacing Refer to Chapter 3 Diagnostics to correct any flowcell and or transd
10. a 3 16 in nutdriver remove the four nut washer sets that secure the display shroud to the inside of the console cover Lift the display shroud off its mounting studs 3 Using a 1 4 nutdriver remove the four standoffs that secure the LCD display assembly to the console cover Lift the LCD display assembly off its mounting studs 4 Place the new LCD display assembly over the mounting studs on the console cover and fasten it in place with the four standoffs Make sure that the LCD display assembly is oriented as shown in Figure 9 on page 42 CAUTION Do not overtighten the standoffs or the display assembly may be damaged 5 Position the LCD display cables between the two right side mounting studs and install the display shroud over the mounting studs The top and bottom edges of the shroud are bent at a 90 angle to the main surface and these edges must face inwards toward the display assembly Note One edge of the display shroud is covered with a piece of black electrical tape This side of the shroud should be on the right to protect the cables against abrasion 6 Fasten the display shroud to the console cover with the four sets of nuts washers CAUTION Do not overtighten the nuts or damage to the mounting threads may occur Complete the LCD Display replacement by proceeding to the Installing the Printed Circuit Board section of this chapter 36 DigitalFlow GM868 Service Manual Chapter 4 Parts Replacement 4 7 Inst
11. flow if STANDARD equation is used Tu S UP Transit S usec Displays Skan Tup Td S DN Transit S usec Displays Skan Tdn DT S DeltaT Susec Displays Skan DELTA Tu M UP Transit M usec Displays Measure Tup Td M DN Transit M usec Displays Measure Tdn DT M DeltaT M usec Displays Measure Delta ToffS Skan T Offset Displays dynamically calculated signal usec timing offset in skan signal measurement gt gt 5 z z z z z z z z zZ z PIPEN R se a Z gt gt gt gt gt gt gt z z z p Vinst Vinst Ft s Displays the instantaneous velocity for comparison with Vel without averaging z gt EXIT Last parameter Leave the Diagnostics Menu These options are available only in the Skan Measure mode 3 3 Diagnostic Record Upon leaving the Diagnostic Menu via the EXIT key or the EXIT option on the option bar the display screen will continue to show the last diagnostic parameter that was selected To return to normal measurement mode select a channel to display for a 2 Channel meter only and then select the desired display parameter See Chapter 3 Operation of the Startup Guide for detailed instructions The values for the diagnostic parameters immediately after initial installation of the meter and verification of proper operation should be entered in Table 6 on page 43 These values can then be compared to futu
12. fuse with a new one of the same rating and type Use only 5 x 20 mm Slo Blo fuses having a rating as indicated in Table 7 below and on the rear panel label Table 7 Line Voltages amp Fuse Ratings Line Voltage Fuse Rating 100 120 VAC 1 0 A Slo Blo 220 240 VAC 0 5 A Slo Blo 12 28 VDC 3 0 A Slo Blo 4 Reinstall the black plastic fuse cover and insert the power cord back into the receptacle Then position the power switch in the ON position The Model GM868 flowmeter may now be placed back into service Reconnect the main power and resume taking measurements Note Be sure to record the fuse replacement in Appendix A Service Record 46 DigitalFlow GM868 Service Manual Appendix B Optional Enclosures B 4 Rack Mount Option Card Installation The Model GM868 flowmeter can accommodate up to six option cards in a manner similar to that used in a PC The option cards are installed into sockets on the printed circuit board and they are held in place with a metal bracket A single metal bracket is used to secure all the installed option cards Note Ifthe Model GM666 presently has no option cards installed be sure to purchase the metal mounting bracket along with the first option card Refer to Figure 11 on page 54 and complete the following steps 1 After disconnecting the main power to the meter remove the top panel from the enclosure by removing the four screws indicated WARNING The main power to the
13. installed option card 3 Press F1 F3 to select alarm relay A B or C respectively DigitalFlow GM868 Service Manual 11 Chapter 1 Calibration 1 7 Testing the Alarm Relays cont Note The procedure for testing Alarm Relay A is identical to that for testing Alarm Relays B and C However make sure that the ohmmeter is connected to the desired normally open or normally closed contact of the currently selected relay See Figure 4 on page 11 for the correct pin numbers on the option card terminal block 4 Pressing F1 CLOSE should yield an ohmmeter reading of about zero Pressing F2 OPEN should yield an infinite ohmmeter reading 5 Press F3 to EXIT 6 Repeat the above procedure until both the normally open and normally closed contacts for all three alarm relays have been tested Then proceed to Procedure Options below Procedure Options You have completed testing the alarm relays Do one of the following To calibrate test additional slots press F4 EXIT and proceed to the appropriate section To leave the Calibration Menu press F4 EXIT twice 12 DigitalFlow GM868 Service Manual Chapter 1 Calibration 1 8 Testing the Totalizer Frequency Outputs Totalizer Frequency outputs may be added to the Model GM868 by installing a Totalizer Frequency Option Card in one or more of the six expansion slots Each option card includes four outputs which are designated as A B C and D To test
14. proper components are obtained be sure to specify the serial number of the Model GM868 at the time of purchase DigitalFlow GM868 Service Manual 39 Chapter 4 Parts Replacement no content intended for this page 40 DigitalFlow GM868 Service Manual Chapter 4 Parts Replacement Front View Keypad Cabl Display Cable Nuts amp Washer 4 places Display Shroud Backlight Cabl Cover Ground Wire Internal Ground Connection Fuse Holder Cap DigitalFlow GM868 Service Manual Mounting Screw 8 places Card Guide Bottom View Nuts amp Washers Display Shroud LCD Displa Standoffs 8 places Metal Bracket Option Card Socket Metal Bracket Standoffs typ LVD Shroud Side View Figure 8 Standard Model GM868 Electronics Console Assembly 41 Chapter 4 Parts Replacement Keypad Cable Short Standoff Vertical Components 3 places Long Standoff EPROM U4 3 places Beveled Corner Keypad Connector J50 Display Connector J52 Fasteners typ Option Card Connectors Figure 9 Standard Model GM868 Printed Circuit Board Assembly Rear View Screws or Standoffs Front View DigitalFlow GM868 Service Manual 42 Appendix A Service Record Appendix A Service Record A 1 Introduction Whenever any service procedure is performed on the Model GM868 flowmeter the details of the service should be recorded in this appendix An accurate servi
15. will evaluate the instrument to determine the cause of the malfunction Then one of the following courses of action will then be taken Ifthe damage is covered under the terms of the warranty the instrument will be repaired at no cost to the owner and returned e f GE Sensing determines that the damage is not covered under the terms of the warranty or if the warranty has expired an estimate for the cost of the repairs at standard rates will be provided Upon receipt of the owner s approval to proceed the instrument will be repaired and returned DigitalFlow GM868 Service Manual 57 Warranty no content intended for this page 58 DigitalFlow GM868 Service Manual Certification amp Measurement amp Control Safety Statements GE Infrastructure Products Used in Hazardous Locations Installation and operation manuals in their complete forms along with product specific certification and safety statement sheets are included on the CD provided with the product documentation shipped with each instrument Please read and follow all provided manufacturer s instructions prior to installation and the application of power to your equipment Always observe the following Field wiring shall be rated at least 10 C above rated ambient Connecting cables shall be mounted securely and protected from mechanical damage pulling and twisting Cable entry thread types are identified on the equipment label Cable glands of an ap
16. 0 0 us cet orco A iie Pro Luc oett Lot c ir a ca ate i Ale et De ca 21 20 ESSAIDEUCEREITODI S2 o o enu ett ot oto O tod A IL t e ten Sore bti i 21 2 8r E6 CUGIESKID ACCC eA kt Cot ood dd tec d te aut HUN EL el UEM t dest ttu P os 21 29 ET ANd Og DUEEFIOI di ue eade doe Ubaldo et idus dot a EE 21 LID ES TEMP Mi tia du ales Aas isa lala sata ars 21 SN s scena i aoleu tear aa tua sr a dn RR XU EFL Bed sd mp al ga alee PU a 21 2 Loro SDECIGPIDIDUD e ada ra M ES 22 2 ES EI O s roe ie re e E Cotta ot ica s ta ede etr Co iile Ca a Eu C dts 22 A WSC ca scie ia tt mes A P SL hoe ln fe 22 2 15 E1 Over RONG G2 4i uester teres Chur RENE Cru pte MR UBI RU De ters DM er teg 22 2 LOE TA TONGS DVSETION e a Sito be a a cee a Sa osi 3 22 pile oh EL5SEQUHOFEDTE So ecco eaaet erecti utbs a dac eee Nos iat a A 22 2 18 Screen Messages e te erat ati 4 tri ee oa rca ed ope nda tere e ierit d tat ok 25 Chapter 3 Diagnostics Be LC A ee wie Moa Por A SEE oper Ro ORIS ERIT foa al one f tls Piae ultor 25 32 Displaying Diagnostic POFBifielers sus iss opea a d OW ERR ngs oie XO ERR UR Heh ee IU ANS i wires 25 BS DIBdHOSHCRSSOL E Se Seu oc uet ct tale xp a ve Da eset 0 ati ed Eos 27 345 PlOWCeI PIOBIEINS a es Pta aS ia stiinta A ias de al ao a Au di i Mal Penal ps 28 SALGO ON i Soeur to Tear os tud usati od ua d lt e a e de 28 35 5 2 PIP PROBING A pe tiec lentes od Rn Li 29 3 qransducer AS E E T E ai it EL Pon l Re at ae EPI C o Dee oaza 29 Chapter 4 Parts Replac
17. 00 13 13 333 3 31 84 Figure 10 Model GM868 Rack Mount Enclosure Dimensions ref dwg 712 1076 5 22 2 25 57 133 19 00 483 DigitalFlow GM868 Service Manual 53 Appendix B Optional Enclosures Line Lead Black Option Card Slot Cover Option Card Socke Neutral Lead White typ Analog Output Connector Fuse RS232 Connector CH1 Transducer Connector CH2 Transd C t Ground Lead Green ransducer Connector Power Terminal Block Top ie Mounting Hole places Printed Circuit Board 4 loooooooooooooooo 90000000000000000 0000000000000000 0000000000000000 0000000000000000O lOOOO000000000000 loooooooooooooooo o000000000000000 Display Cable ooooooo 0000000000000000 oo 9939966656 90000000000000000 Red Lead loOopooooooo oooooooooooooooo loOopooooooo o000000000000000 Snap Rivets typ M Option Card Bracket Beveled Corner PCB Mounting Screw typ Figure 11 Model GM868 Rack Mount Console Assembly ref dwg 705 849 Black Lead m EPROM U4 Backlight Cabl
18. GE Measurement Control Flow DigitalFlow GM868 Panametrics Multipurpose Ultrasonic Gas Flowmeter Service Manual ai work 910 1935 Rev F agination a O February 2015 DigitalFlow GM868 Panametrics Multipurpose Ultrasonic Gas Flowmeter Service Manual 910 1935 Rev F February 2015 WWW ge mcs com 2015 General Electric Company All rights reserved Technical content subject to change without notice no content intended for this page Preface Information Paragraphs Note These paragraphs provide information that provides a deeper understanding of the situation but is not essential to the proper completion of the instructions IMPORTANT These paragraphs provide information emphasizing instructions which are essential to proper setup of the equipment Failure to follow these instructions carefully may cause unreliable performance WARNING Indicates a potentially hazardous situation which can result in serious personal injury or death if it is not avoided CAUTION Indicates a potentially hazardous situation which can result in minor or moderate injury to personnel or damage to the equipment if it is not avoided HIGH VOLTAGE This symbol indicates the presence of high voltage It calls your attention to situations or operations that could be dangerous to you and other persons operating the equipment Read these messages and follow the instructions carefully Safety Issues WARNING It is t
19. Model GM868 must be disconnected before proceeding 2 Ifone or more option cards are already installed remove the four fasteners that secure the metal bracket to the printed circuit board Lift the metal bracket straight up and away from the printed circuit board Note The fasteners may be either plastic snap rivets or metal hardware in some older meters In either case they may be discarded as new plastic snap rivets will be provided 3 There are six 32 pin option card sockets J41 J46 on the rear of the printed circuit board By removing the screw on the rear panel remove the appropriate option slot cover to make room for the external connector on the new option card 4 To install the option card insert its 32 pin connector into the chosen option card socket and gently press the card into place Make sure that the pins in the connector are straight and properly aligned with the socket and that the option card is oriented with its external connector positioned in the opening on the rear panel CAUTION Do not force the option card into the socket If the card does not enter the socket easily check for and straighten any bent pins in the connector and try again 5 Repeat steps 3 and 4 to install any additional option cards 6 Place the metal bracket over the option cards making sure that all installed option cards are inserted into the plastic card guides in the bracket The bracket must be oriented so that the six card guides a
20. NT 1 6 36 Slope Number 5 Press F2 to enter the slope number Calculate the slope number with the formula Slope Slope points set points slope temp set temp 6 Enter the RTD slope number and press ENT Procedure Options You have completed calibration of the RTD input Do one of the following To calibrate another input press EXIT e To calibrate additional slots press EXIT and then F4 EXIT and proceed to the appropriate section To leave the Calibration Menu press F4 EXIT twice 10 DigitalFlow GM868 Service Manual Chapter 1 Calibration 1 7 Testing the Alarm Relays Alarm relays may be added to the Model GM868 by installing an Alarms Option Card in one or more of the six expansion slots Each option card includes three alarm relays which are designated as A B and C To test the alarm relays connect an ohmmeter to the option card terminal block as shown in Figure 4 below Refer to the menu map in Figure 6 on page 15 as a guide Terminal Block Option Card Ohmmeter Figure 4 Typical Ohmmeter Connections For this discussion assume that the option card has been installed in Slot x 1 7 1 Accessing the Calibration Menu 1 Press the CAL key to enter the Calibration Program 2 Press Fx to calibrate the desired slot The option bar will include a slot listing for each
21. a result accurate flow rate measurements are not possible Realignment of the flowcell or transducers often cures such problems and in some cases transducers that protrude into the flow stream may be used Refer to Chapter 1 Installation of the Startup Guide for more details on proper installation practices 2 Inaccurate pipe measurements The accuracy of the flow rate measurements is no better than the accuracy of the programmed pipe dimensions For a flowcell supplied by GE the correct data will be included in the documentation For other flowcells measure the pipe wall thickness and diameter with the same accuracy desired in the flow rate readings Also check the pipe for dents eccentricity weld deformity straightness and other factors that may cause inaccurate readings Refer to Chapter 2 Initial Setup of the Startup Guide for instructions on programming the pipe data In addition to the actual pipe dimensions the path length P and the axial dimension L based on the actual transducer mounting locations must be accurately programmed into the flowmeter For a GE flowcell this data will be included with the documentation for the system If the transducers are mounted onto an existing pipe these dimensions must be precisely measured See Appendix D Measuring P and L Dimensions of the Startup Guide for a thorough discussion of this topic 3 5 Transducer Problems Ultrasonic transducers are rugged reliable devices However they ar
22. alling the Printed Circuit Board Whether the printed circuit board was removed for replacement or for one of the other procedures discussed in this chapter reinstallation of the printed circuit board is the final step in the process Refer to Figure 8 on page 41 and complete the following steps CAUTION During this procedure be very careful not to damage the vertical components along the top edge of the printed circuit board see Figure 9 on page 42 Severe or repeated bending of these components will break their leads 1 Position the printed circuit board within the electronics console with the top edge tilted forward Insert the display ribbon cable and keypad ribbon cable connectors into their sockets on the rear of the printed circuit board See Figure 8 on page 41 and Figure 9 on page 42 to identify the cables and sockets Note that the keypad cable connects to the upper socket and the display cable connects to the lower socket IMPORTANT The ribbon cables must be installed with the edges that were marked during removal oriented toward the top of the printed circuit board 2 Carefully position the printed circuit board up against the eight standoffs in the enclosure Do not damage the transformers and any installed option cards as they are maneuvered between the standoffs 3 Loosely install the three long standoffs on the right side of the printed circuit board and the two standoffs or screws along the bottom edge of the printed circ
23. anty is effective from the date of delivery to the original purchaser If GE Sensing determines that the equipment was defective the warranty period is e one year from delivery for electronic or mechanical failures one year from delivery for sensor shelf life If GE Sensing determines that the equipment was damaged by misuse improper installation the use of unauthorized replacement parts or operating conditions outside the guidelines specified by GE Sensing the repairs are not covered under this warranty The warranties set forth herein are exclusive and are in lieu of all other warranties whether statutory express or implied including warranties or merchantability and fitness for a particular purpose and warranties arising from course of dealing or usage or trade Return Policy If a GE Sensing instrument malfunctions within the warranty period the following procedure must be completed 1 Notify GE Sensing giving full details of the problem and provide the model number and serial number of the instrument If the nature of the problem indicates the need for factory service GE Sensing will issue a RETURN AUTHORIZATION NUMBER RAN and shipping instructions for the return of the instrument to a service center will be provided 2 If GE Sensing instructs you to send your instrument to a service center it must be shipped prepaid to the authorized repair station indicated in the shipping instructions 3 Uponreceipt GE Sensing
24. ce history of the meter can prove very helpful in troubleshooting any future problems A 2 Data Entry Record complete and detailed service data for the Model GM868 in Table 6 below Make additional copies of the table as needed Table 6 Service Record Description of Service Performed By DigitalFlow GM868 Service Manual 43 Appendix A Service Record Table 6 Service Record cont Description of Service Performed By 44 DigitalFlow GM868 Service Manuall Appendix B Optional Enclosures Appendix B Optional Enclosures B 1 Introduction The Model GM868 is available in optional enclosure types each of which has been designed to permit easy on site upgrades and parts replacement See the foldout drawings at the end of this appendix for details of the applicable GM868 electronics console assembly The instructions in this appendix along with a few common tools are all that is required to perform the following tasks e fuse replacement e option card installation EPROM replacement LCD display replacement printed circuit board PCB replacement IMPORTANT For meters supplied in the standard Type 4X enclosure see Chapter 4 Parts Replacement for instructions specific to that unit WARNING Prior to performing any maintenance procedures disconnect the main power from the unit Note For compliance with the E
25. compliant units remove the two mounting screws and lift the clear plastic shroud out of the electronics console 2 Locate the black plastic fuse holder that is mounted on the printed circuit board between the power terminal block TB1 and the RS232 terminal block As shown in Figure 8 on page 41 the fuse holder extends below the main aluminum shroud and the fuse holder cap is located on the bottom of the fuse holder 3 Using a small standard screwdriver turn the fuse holder cap counterclockwise about 1 4 turn The fuse holder cap with the captive fuse will be ejected from the fuse holder 4 Replace the defective fuse with a new one of the same rating and type Use only 1 1 4 x 1 4 Slo Blo fuses having a rating as indicated in Table 4 below and on the wiring diagram label Table 4 Line Voltages amp Fuse Ratings Line Voltage Fuse Rating 100 120 VAC 1 0 A Slo Blo 220 240 VAC 0 5 A Slo Blo 12 28 VDC 3 0 A Slo Blo 5 Press the new fuse into the fuse holder cap and insert the fuse into the fuse holder While applying a slight pressure with the screwdriver twist the fuse holder cap 1 4 turn clockwise 6 For LVD compliant units place the clear plastic shroud over the standoffs in the electronics console and secure it in place with its two mounting screws Close the cover on the electronics console The Model GM868 flowmeter may now be placed back into service Reconnect the main power and resume taking measure
26. d recalling a site there are no site files to recall All Sites Cleared hit key Clearing a site there are no sites to delete printing a site there are no sites to print displaying a site there are no sites to display Hit any key to resume taking measurements This message appears upon exiting the User Program if the new site data has not been saved Failure to save will result in loss of the 2 PO ASA new data next time the site data is changed or recalled Duplicate name The site file or log name is already in use Enter a different name Enter another DigitalFlow GM868 Service Manual 23 Chapter 2 Error Codes and Screen Messages Table 2 Screen Messages cont ig End Time must exceed Start Time by 5 min This message appears when in the LOG menu Enter an end time that is at least five minutes later than the start time Header invalid An option card error indicating a programming failure or a loss of memory Contact the factory Log Active END only hit any key When in the LOG menu this message indicates that the log is still compiling data Only the End Time may be edited Log DONE to inspect hit any key When in the LOG menu this message indicates that the log is complete Hit any key to display the log Log hasn t started hit key When in the LOG menu this message indicates that the log has not yet started OK settling The measurement has not stabilize
27. d Wait before taking a reading Outside limits value rejected Overflow When in the CAL menu this message indicates that the calibration of the analog output is invalid Hit any key to clear the message and the GM868 will default to the last valid calibration The message will also appear if there is no ammeter connected to the analog output during calibration The display value overflowed Reduce the number of decimal digits or change the units P L Enter L again The entered path length P is less than the axial dimension L Enter a new value for L range is X XX to X XX When in the User Program this message indicates that the entered number is unacceptable Hit any key and enter a number within the allowable range Review calibration An option card error indicating a programming failure or a loss of memory Contact the factory Review parameters An option card error indicating a programming failure or a loss of memory Contact the factory Staring time must exceed current time This message appears when in the LOG menu STD option Enter a start time that is later than the current time Write error 24 An option card error indicating a programming failure or a loss of memory Contact the factory DigitalFlow GM868 Service Manual Chapter 3 Diagnostics Chapter 3 Diagnostics 3 1 Introduction This chapter explains how to troubleshoot the Model GM868 if proble
28. difference in usec between N A 710 000 upstream and downstream transit times nsec PEAK PEAK Displays the percentage of peak N A N A set to 50 by default Qup UP Signal Q Displays the signal quality for the 2 1200 400 to upstream transducer 400 Qdown DN Signal Q Displays the signal quality for the gt 1200 400 to downstream transducer 400 AMPup UP Amp Discrim Displays the value for the amplitude 24 5 lt 19 or gt 29 discriminator of the upstream transducer AMPdn DN Amp Discrim Displays the value for the amplitude 24 5 19 or gt 29 discriminator of downstream transducer CNTup UP DAC Counts Displays the AGC DAC count for N A N A upstream gain setting CNTdn DN DAC Counts Displays the AGC DAC count for N A N A downstream gain setting 26 DigitalFlow GM868 Service Manual Chapter 3 Diagnostics Table 3 Available Diagnostic Parameters cont Option Bar Screen Display Description Good P up UP Peak Displays signal peaks for the upstream 100 230 transducer 0 DN Peak Displays signal peaks for the 100 230 100 or downstream transducer 0 gt 2300 Temperature deg Displays the gas temperature A F 4 20 mA input Pressure psia Displays the gas pressure A 4 20 mA input Mw Molecular Wt Displays the average molecular weight of the gas AcVOL Act Vol KACF MIN Displays actual volumetric flow StVOL Std Vol KSCF MIN Displays standard volumetric
29. e Directive this unit requires an external power disconnect device such as a switch or circuit breaker The disconnect device must be marked as such clearly visible directly accessible and located within 1 8 m 6 ft of the Model GM868 The power cord is the main disconnect device An aluminum shroud over the printed circuit board shields the electrical components and serves as a location for the wiring diagram label All of the procedures discussed in this chapter except for fuse replacement require removal of this shroud Note For compliance with the European Union s Low Voltage Directive a transparent plastic shroud protects the electrical connections The shroud must remain in place except while wiring the unit Reinstall the shroud after the wiring has been completed Use the foldout drawings at the end of this chapter to locate the relevant components while completing the following procedures IMPORTANT Keep a detailed record all service procedures performed on the Model GM868 in Appendix A Service Record This service history may prove very helpful in diagnosing any future problems DigitalFlow GM868 Service Manual 31 Chapter 4 Parts Replacement 4 2 Fuse Replacement If it has been determined that the fuse in the Model GM868 requires replacement complete the following steps WARNING The main power to the Model GM868 must be disconnected before proceeding 1 Open the cover on the electronics console For LVD
30. e ae 34 User Pros se 34 Error Codes ao id t 20 21 Error Message Display Screen 19 Expansion lO e its At e EE 1 F Flowcell Problems A oie cutus BERN Otay jo Sul d d je eta 28 A SEU d OR OE Res Sano a Sep E 29 Fuse Holder sud cese ER RE SVP Rb SIE 32 TIC OE RR IT TEES TE CETT I 32 Replacing sooroo noran tioman aiii a CIE 32 Se a atata EET 32 A AEE e ta Mn Bari o ed E 32 G Gas Contamitiatiol cec E Ua ES 28 Physical Requirements seen 28 Problems 4 ped eo oae he 8 aie ced 28 SOUndsPegd uit as ostras Deed 28 Grounding Straps 222v Celer het ERE d Mata a 37 Guides Option Card cid WEE 35 K Keypad Cable tas a er 33 L LCD Display o n cate RACE rci it gets 36 Leaks Transducers 0 000 ee eee eee 29 Low Signal Error El cos alas 20 LVD Stma 0e daiwa auae 31 N No Ertor EQ 22 29 4d m e ak aw woe Ros 20 Numer Option for RTD Option Card sortir as 10 55 Index O Option Card Analog UIDES ia a 2 Brackets a as 35 Expansion Slots 4 255 a ete oo ia 1 Guides ads dedo best tas pa da a 35 INStANNAG avs Sus a Aza 35 Sockets tos 1x das sett od dd a 35 Over Range Error El3 22 P Pipe Measurements llle 29 Problems sida rr PUER E Eats 29 Pressure Input Error E9 oro cede bo es 21 Printed Circuit Board EPROM pia ace Ael a 34 Replace rr 33 PROBE Option for RTD Option Card 5 2 ss e a 9 Problems TransducerS lt lt 29 R Reboot Automatic eee 1 Replacing
31. e by connecting an ammeter to the desired analog output of Slot X as shown in Figure below and Figure 2 on the next page Refer to the menu map in Figure 6 on page 15 Terminal Block I O Slot 0 Ammeter Figure 1 Ammeter Connection for Slot 0 Output A 2 DigitalFlow GM868 Service Manual Chapter 1 Calibration 13 Calibrating the Analog Outputs cont Terminal Block Option Card Ammeter Figure 2 Ammeter Connection for Slots 1 6 Output A DigitalFlow GM868 Service Manual 3 Chapter 1 Calibration 1 4 Accessing the Calibration Menu 1 Press the CAL key to enter the Calibration Program 2 Press Fx to calibrate the desired slot The option bar will include a slot listing for each installed option card 3 Press Fx to select the desired output IMPORTANT The procedure for calibrating all the outputs is the same However when calibrating a different output be sure to reconnect the ammeter to the appropriate pins on terminal block I O See Figure 1 on page 2 or Figure 2 above for the correct pin numbers 1 4 4 Calibrating the Low End of the Output Range 1 Press F1 to calibrate the low end of the output range 2 Press F1 or F2 to adjust the ammeter reading UP or DOWN until a 4 mA reading is achi
32. e subject to physical damage from mishandling and chemical attack The most common transducer problems are listed below 1 LEAKS Leaks may occur around the transducer and or the flowcell fittings Repair such leaks immediately If the leaking gas is corrosive carefully check the transducer and cables for damage after the leak has been repaired 2 CORROSION DAMAGE If the transducer material was not properly chosen for the intended application the transducers may suffer corrosion damage The damage usually occurs either at the electrical connector or on the transducer surface If corrosion is suspected remove the transducer from the flowcell and carefully inspect the electrical connector and the transducer surface for roughness and or pitting Any transducer damaged in this manner must be replaced Contact the factory for information on transducers in materials suitable for the application 3 INTERNAL DAMAGE An ultrasonic transducer consists of a ceramic crystal bonded to the transducer case The bond between the crystal and the case or the crystal itself may be damaged by extreme mechanical shock and or temperature extremes Also the internal wiring can be corroded or shorted if contaminants enter the transducer housing 4 PHYSICAL DAMAGE Transducers may be physically damaged by dropping them onto a hard surface or striking them against another object The transducer connector is the most fragile part and is the one most subject to damage
33. ed circuit board To install an option card insert its 32 pin connector into any available option card socket and gently press the card into place Make sure that the pins in the connector are straight and properly aligned with the socket and that the connector is positioned on the right side of the option card CAUTION Do not force the option card into the socket If the card does not enter the socket easily check for and straighten any bent pins in the connector and try again 4 Repeat step 3 to install any additional option cards 5 Place the metal bracket over the option cards making sure that all option cards are aligned with the plastic card guides in the bracket Secure the metal bracket to the printed circuit board with the snap rivets provided See the installed assembly in Figure 8 on page 41 Complete the option card installation by proceeding to the Installing the Printed Circuit Board section of this chapter DigitalFlow GM868 Service Manual 35 Chapter 4 Parts Replacement 4 6 Replacing the LCD Display The Model GM868 s measurements are displayed on a a two pane LCD graphic display panel The LCD display normally provides years of dependable service but it is easily field replaceable when necessary To replace the LCD display see Figure 8 on page 41 for the component locations and complete the following steps 1 Remove the printed circuit board as described in a previous section of this chapter 2 Using
34. el GM868 must be disconnected before proceeding 2 Disconnect all external option card connectors at the rear panel of the meter Then remove all installed option cards from the printed circuit board as described earlier in this chapter 3 Disconnect the main POWER LEADS from the screw terminals at the rear of the printed circuit board Make a sketch of the terminal block and the locations of the black white and green power leads to assist in reinstallation on the new circuit board 4 Remove the RS232 ANALOG OUT and TRANSDUCER connectors from the printed circuit board Use a marker to identify pin 1 on the right side keypad side of these connectors Note These connectors should be pulled straight up and off the printed circuit board DO NOT remove the leads from the screw terminals 5 Remove the flat KEYPAD CABLE connector from terminal J50 near the front of the printed circuit board Mark pin 1 of the cable connector which is located nearer the rear of the enclosure 6 Disconnect the twisted pair DISPLAY BACKLIGHT cable from connector J2 beneath the left side of the printed circuit board Although this connector is polarized it will help to note that the red wire is closer to the rear of the enclosure 7 Remove the flat LCD DISPLAY CABLE connector from terminal J52 near the option card sockets Mark pin 1 of the cable connector which is located nearer the front of the enclosure 8 Using a slotted screwdriver remove the t
35. ement AL VIOREL REOR tei ap r A A E 31 42 spise ReplacelmiBhb cocos e PIT eta SUPPE be E whee add ees tabou ae oad a 32 4 5 Removing the Printed Circuit Board a xi doa petto per Er Ure shaw ERR R AG ale gla NW PER ERAS MES 33 E RODIOGING The E e D ME Aut Ma E ae A 34 A stel dac DEDE OE secet e os ucciso rcu Led NU LO e M me De I 55 45 Replacing the LCD MSNA ase saca ai caca a e ln EE t LI o Lr te de CT e ia 36 au Stalling the Printed Circuit BOSE eaea dl ecl domu cte Ga 37 48 SpareiPdbtsa 5 oec eese ee RENE hcc edd det ve er pie a ad Tutus 39 Appendix A Service Record Azle E der bebe tutt Nd E Nd ERE ELI d Oe eee i i Oa ee 43 A2 Data Entrys sc eda EE hed eR Ped ad IUe Pendet i e T de ne Ud 43 vi DigitalFlow GM868 Service Manual Contents Appendix B Optional Enclosures 8 1 B 2 B 3 B 4 B 5 B 6 B 7 A A A A M ERN LE 45 Rack MORE ERE O O e titt 45 Rack M nt Fise REC a dl id 46 ROC ENOUALOBHON CASAN a eese t ed ln id 47 ROCK Mount EPROMIRSDIGEBETBEIS S statis e OA epos e de de nv ed 48 Rack Mount LCD Display Replacement sos ce etsi ctio sed a tU aceite ear ere e 49 Rack Mount Printed Circuit Board Replacement ie 2 oet c Ce a e redes 50 B LeIreubBodd REMOVALS i259 DEC ERO ML UE A tutt st dtt Rae Sar 50 B2 Circuit Board installation se opos ue edi EPI I Rp thea ca aber 51 e Special Conditions tor Safe Sg sarete ira ERER dro Io Rea E Ea da Ep bU Ln ata a aT SEAT dta A ARR RI 2 DigitalFlow GM868 Service Ma
36. emperature gradients in the gas flow may result in erratic or inaccurate flow rate readings 2 The gas must not excessively attenuate ultrasound signals Some gases 1 e high purity carbon dioxide hydrogen etc readily attenuate ultrasound energy In such a case an E1 error code message will appear on the display screen to indicate that the ultrasonic signal strength is insufficient for reliable measurements 3 The gas sound speed must not vary excessively The Model GM868 will tolerate relatively large changes in the gas sound speed as may be caused by variations in gas composition and or temperature However such changes must occur slowly Rapid fluctuations in the gas sound speed to a value that is considerably different from that programmed into the Model GM868 will result in erratic or inaccurate flow rate readings Refer to Chapter 2 Initial Setup of the Startup Guide and make sure that the appropriate sound speed is programmed into the meter 28 DigitalFlow GM868 Service Manual Chapter 3 Diagnostics 3 4 2 Pipe Problems Pipe related problems may result either from a failure to observe the installation instructions as described in the Startup Guide or from improper programming of the meter By far the most common pipe problems are the following 1 The collection of material at the transducer location s Accumulated debris at the transducer location s will interfere with transmission of the ultrasound signals As
37. emperature should be as far from your set point as your temperature bath will allow within the range 100 to 350 C 8 Enter the desired slope point temperature and press ENT 9 Press F1 to STORE the entered temperature or F2 to ABORT the calibration In either case the screen returns to the ANALOG INPUT prompt 10 Proceed to Procedure Options on the next page DigitalFlow GM868 Service Manual 9 Chapter 1 Calibration 1 6 3 Numer Option F2 The Numer option forces the user to calculate the temperature vs resistance information To do this the user must first collect data using the RTDs option in the PRINT menu discussed in Chapter 5 of the Programming Guide The RTDs option allows you to know what point value the GM868 is reading at a given temperature With this information the Numer option enables you to enter the Set Temperature and the slope of the RTD input in points degree allowing absolute control over RTD calibration Before attempting this step follow the instructions in Chapter 5 of the Programming Manual The RTDs Submenu to obtain point values at your set point and slope point 1 Press F1 to select Input A or F2 to select Input B 1 6 3a Set Number 2 Press F1 to enter the set number formerly known as the zero point 3 Enter the set point temperature and press ENT 4 The program then asks for the set point number Enter the points measured at the set temperature and press E
38. er the mounting studs The top and bottom edges of the shroud are bent at a 90 angle to the main surface and these edges must face inwards toward the display assembly Note One edge of the display shroud is covered with a piece of black electrical tape This side of the shroud should be over the cables to protect them against abrasion 7 Fasten the display shroud to the front panel with the four sets of nuts washers CAUTION Do not overtighten the nuts or damage to the mounting threads may occur 8 After checking for any loose hardware that may have fallen into the enclosure reinstall the top panel on the meter and secure the panel in place with the four screws previously removed The Model GM868 flowmeter may now be placed back into service Reconnect the main power and resume taking measurements Note Be sure to record the LCD Display replacement in Appendix A Service Record DigitalFlow GM868 Service Manual 49 Appendix B Optional Enclosures B 7 Rack Mount Printed Circuit Board Replacement If troubleshooting procedures have indicated a defective printed circuit board follow the instructions in this section to replace the defective board with a new one B 7 1 Circuit Board Removal Refer to Figure 11 on page 54 and complete the following steps 1 After disconnecting the main power to the meter remove the top panel from the enclosure by removing the four screws indicated WARNING The main power to the Mod
39. error code message is not currently in use 2 14 E12 Not Used This error code message is not currently in use 2 15 E13 Over Range Problem This error code message indicates that the present measurement exceeds the capacity of the meter Cause A internal mathematical overflow has occurred in either the volumetric or mass flow calculations Action Select larger measurement units or a shorter time interval for the current measurement parameter For example choose KSCF M instead of SCF M See the Startup Guide for instructions 2 16 E14 Totals Overflow Problem The totalizers are unable to keep up with the total flow signals Cause The programmed units pulse value is too small Action Select a larger number of units pulse value 2 17 E15 Equation Limit Problem The steam measurement may not be within 1 accuracy Cause The temperature or pressure reading is outside the accuracy specification of the GM868 steam equations Action Adjust the pressure reading to within the range of 139 9685 kPa to 2242 9435 kPa or the temperature reading to within the range of 373 1500K to 810 9278K 22 DigitalFlow GM868 Service Manual Chapter 2 Error Codes and Screen Messages 2 18 Screen Messages A variety of messages may appear on the display screen during the performance of a task Since the error codes have already been discussed in this chapter and the locator bar messages are discussed in detail in Chapter 3 Operation of
40. eved If you press F3 Numer enter a numeric value for the calibration point and press ENT 3 Press F4 to STORE the setting or press gt and F1 to ABORT the calibration Note Ifthe ammeter reading cannot be adjusted within 5 0 uA of the 4 mA setting contact the factory for assistance 1 4 2 Calibrating the High End of the Output Range 1 Press F2 to calibrate the high end of the output range 2 Press F1 or F2 to adjust the ammeter reading UP or DOWN until a 20 mA reading is achieved If you press F3 Numer enter a numeric value for the calibration point and press ENT Note Ifthe ammeter reading cannot be adjusted within 5 0 UA of the 20 mA setting contact the factory for assistance 3 Press F4 to STORE the setting or press gt and F1 to ABORT the calibration Note Skip the next section if the linearity test will not be performed at this time Proceed to Procedure Options on the next page 1 4 3 Testing the Analog Output Linearity Note Ifyou exited this menu and are returning follow steps 1 through 3 in Accessing the Calibration Menu on page 4 Press F3 to TEST the linearity of the currently selected analog output Check the ammeter reading at the 50 output level Then enter a different output level 0 100956 and press ENT A E Check the ammeter reading at this setting and press ENT when done Table 1 on the next page lists the expected ammeter readings at various Full Scale settings
41. ever you access the card in the same manner as other cards 1 6 1 Accessing the Calibration Menu 1 Press the CAL key to enter the Calibration Program 2 Press Fx to calibrate the desired slot The option bar will include a slot listing for each installed option card If you have installed an RTD option card the following screen appears Press F1 to select the Probe method of calibration or F2 to select the Slot x Inputs numeric method current input selected RTD CALIBRAT last option selected Probe Numer l l The Probe option allows the meter to calculate the temperature vs resistance curve based on input from the RTD in a temperature bath or from an RTD calibrator The Numer option forces the user to calculate and input the curve values numerically IMPORTANT Use only one option for RTD calibration Do not try to calibrate with both options 1 6 2 Probe Option F1 3 Press F1 to select Input A or F2 to select Input B 1 6 2a Set Point Temperature 4 Press F1 to enter the set point temperature formerly known as the zero point This temperature should be at the low end of your expected operating range 5 Enter the desired set point temperature and press ENT 6 Press F1 to STORE the entered temperature or F2 to ABORT the calibration In either case the screen returns to the ANALOG INPUT prompt 1 6 26 Slope Point Temperature 7 Press F2 to enter the slope point temperature This t
42. he next page apply to both the 1 Channel and 2 Channel versions of the Model GM868 flowmeter The following discussion assumes that the left screen pane is active If the right screen pane is active only the function key designations change That is replace F1 F4 with F5 F8 Proceed to the appropriate sections of this chapter to calibrate and test all of the installed inputs and or outputs Note While in the Calibration Menu if there is no keypad activity for two minutes the Model GM868 will automatically reboot and return to measurement mode DigitalFlow GM868 Service Manual 1 Chapter 1 Calibration 1 3 Calibrating the Analog Outputs Every Model GM868 flowmeter includes two built in analog outputs A and B at terminal block 1 0 which is designated as Slot 0 Additional analog outputs may be added to the Model GM868 by installing an Analog Outputs Option Card in one or more of the six expansion slots Each option card contains four analog outputs which are designated as A B C and D Both the zero point and full scale values for each output must be calibrated After calibrating the outputs which have a resolution of 5 0 uA 0 03 full scale their linearity should be tested Note The zero point of the analog output may be set for either 0 mA or 4 mA However the calibration procedure always uses the 4 mA point as the meter will extrapolate this value to obtain the 0 mA point Prepare for the calibration procedur
43. he responsibility of the user to make sure all local county state and national codes regulations rules and laws related to safety and safe operating conditions are met for each installation gt Auxiliary Equipment Local Safety Standards The user must make sure that he operates all auxiliary equipment in accordance with local codes standards regulations or laws applicable to safety Working Area WARNING Auxiliary equipment may have both manual and automatic modes of operation As equipment can move suddenly and without warning do not enter the work cell of this equipment during automatic operation and do not enter the work envelope of this equipment during manual operation If you do serious injury can result WARNING Make sure that power to the auxiliary equipment is turned OFF and locked out before you perform maintenance procedures on the equipment DigitalFlow GM868 Service Manual iii Preface Qualification of Personnel Make sure that all personnel have manufacturer approved training applicable to the auxiliary equipment Personal Safety Equipment Make sure that operators and maintenance personnel have all safety equipment applicable to the auxiliary equipment Examples include safety glasses protective headgear safety shoes etc Unauthorized Operation Make sure that unauthorized personnel cannot gain access to the operation of the equipment Environmental Compliance Waste Electrical and Electron
44. heses above appears in the locator bar only with a 2 Channel Model GM868 For example pressing F1 displays the Tdown parameter as shown in the following prompt DigitalFlow GM868 Service Manual 25 Chapter 3 Diagnostics 3 2 Displaying Diagnostic Parameters cont Ch1 label gSITE gt Press the and gt keys and the appropriate Fx key to display a different Ch1 DN Transit usec diagnostic parameter or to EXIT the Diagnostics Menu 919 7 error codes appear here Table 3 below lists the available diagnostic parameters for the Model GM868 The first column in the table shows the parameter as it appears on the option bar while the second column shows the parameter as it appears in the prompt area after it has been selected Table 3 Available Diagnostic Parameters Option Bar Screen Display Description Ss up UP Sig Strength Displays the signal strength for the 50 75 lt 50 or gt 75 upstream transducer SS do DN Sig Strength Displays the signal strength for the 50 75 lt 50 or gt 75 downstream transducer SNDSP Soundspeed Ft s Displays the measured sound speed of N A N A the fluid Tup UP Transit S usec Displays the upstream transit time of the N A N A ultrasonic signal in microseconds Tdown DN Transit usec Displays the downstream transit time of N A N A the ultrasonic signal in microseconds DELTA DeltaT usec Displays the
45. hree mounting screws along each side of the printed circuit board Carefully lift the printed circuit board out of the enclosure Proceed to the next section for instructions on installing the new printed circuit board 50 DigitalFlow GM868 Service Manual Appendix B Optional Enclosures B 7 2 Circuit Board Installation Refer to Figure 11 on page 54 and complete the following steps 1 Position the new printed circuit board within the electronics console so that it rests on the six standoffs in the base of the enclosure and the option card sockets are located near the rear of the enclosure Secure the circuit board in place with the six screws previously removed 2 Connect the flat LCD DISPLAY CABLE connector to terminal J52 near the option card sockets Make sure the marked pin 1 side of the cable connector is located nearer the front of the enclosure 3 Connect the twisted pair DISPLAY BACKLIGHT cable to connector J2 beneath the left side of the printed circuit board This connector is polarized and can only be installed with the red wire closer to the rear of the enclosure 4 Connect the flat KEYPAD CABLE connector to terminal J50 near the front of the printed circuit board Make sure the marked pin 1 side of the cable connector is located nearer the rear of the enclosure 5 Install the RS232 ANALOG OUT and TRANSDUCER connectors onto the printed circuit board at the locations indicated in Figure 11 on page 54 Make sure the
46. iate section To leave the Calibration Menu press F4 EXIT twice 14 DigitalFlow GM868 Service Manual Chapter 1 Calibration DigitalFlow GM868 Service Manual Slot 0 Outputs TB I O F2 La e ANALOG OUTPUT F1 F2 F3 F4 4mA 20mA TEST EXIT Full Scale CALIBRATING UP Down Numer STORE ABORT Numeric Slot x Outputs Analog Outputs uP Down Numer STORE ABORT Numeric En En a E E em SLOT6 Slot x Option Card Slot x Inputs Analog Inputs F2 AJ ET ANALOG INPU F1 F2 F3 F4 F1 laLOW aHIGH 4mA 20 mA EXIT LOW REFERENCE HIGH REFERENCE LOW REF HIGH REF CALIBRATING F2 STORE ABORT STORE ABORT RTD Inputs F2 F2 LB Probe Numer F1 F2 F1 F2 SetPt Slope Seti Slop Set Point Slope Number Temp Set Point Slope Point F1 F2 Set NOTE STORE ABORT Slot x Outputs Alarms CLosB OPEN EXIT Slot x Outputs Freq Total F1 F2 F3 F4 Cee Ea FREQUENCY PULSES Plain text represents prompt area messages and boxed text represents option bar choices Fx represent function keys to select option bar choices Figure 6 Calibration Menu Map 15 Chapter 1 Calibration DigitalFlow GM868 Service Manual 16 Chapter 2 Error Codes and Screen Messages Chapter 2 Error Codes and Screen Messages 2 1 I
47. ic Equipment WEEE Directive GE Measurement amp Control is an active participant in Europe s Waste Electrical and Electronic Equipment WEEE take back initiative directive 2012 19 EU The equipment that you bought has required the extraction and use of natural resources for its production It may contain hazardous substances that could impact health and the environment In order to avoid the dissemination of those substances in our environment and to diminish the pressure on the natural resources we encourage you to use the appropriate take back systems Those systems will reuse or recycle most of the materials of your end life equipment in a sound way The crossed out wheeled bin symbol invites you to use those systems If you need more information on the collection reuse and recycling systems please contact your local or regional waste administration Visit http www ge mcs com en about us environmental health and safety weee html for take back instructions and more information about this initiative iv DigitalFlow GM868 Service Manual Contents Chapter 1 Calibration 1 1 1 2 1 3 1 4 1 5 1 6 1 7 1 8 A CST EE 1 Menu Ndps etos ir aa E e PED ee won to adi a o dd 1 Calibrating the US eel O 2 Accessing tie CODO a e d ad a e eo 4 1 4 1 Calibrating the Low End of the Output A e apis bs 4 1 4 2 Calibrating the High End of the Output Range sea aan ca ae a cete e 4 1 4 3 Testing the Analog Output Linearity Se
48. ion F2 1 2 3 Enter the high reference value and press the ENT key Press F1 to store the current high reference value or press F2 to cancel the entry In either case the ANALOG INPUT prompt will reappear Proceed to Procedure Options below 1 5 4 4 mA Option F3 1 2 3 Connect the 4 mA current source to the currently selected analog input as shown in Figure 3 on page 6 Press F1 to store the current 4 mA value or press F2 to cancel the entry In either case the ANALOG INPUT prompt reappears Press F4 to proceed to the next section 1 5 5 20 mA Option F4 1 2 3 Connect the 20 mA current source to the currently selected analog input as shown in Figure 3 on page 6 Press F1 to store the current 20 mA value or press F2 to cancel the entry In either case the ANALOG INPUT prompt reappears Proceed to Procedure Options below Procedure Options You have completed calibration of the analog output Do one of the following To calibrate another input return to Step 3 in Accessing the Calibration Menu on the previous page To calibrate test additional slots press F4 EXIT and proceed to the appropriate section To leave the Calibration Menu press F4 EXIT twice DigitalFlow GM868 Service Manual Chapter 1 Calibration 1 6 Calibrating the RTD Inputs Calibrating an RTD option card involves a different procedure than for other analog input cards How
49. ircuit board Note For an LVD compliant meter with the clear plastic shroud over the electrical connectors there will be standoffs in these two locations For meters not equipped with this shroud there will be Phillips head screws in these two locations 6 Carefully lift the printed circuit board out of the enclosure Continue to support the printed circuit board as the keypad and display cables are still connected to the rear of the board CAUTION During this procedure be very careful not to damage the upright components along the top edge of the printed circuit board see Figure 9 on page 42 Severe or repeated bending of these components will break their leads 7 Tilt the top of the printed circuit board forward and mark the top edges of the two ribbon cable connectors Then remove these cables from their connectors on the rear of the board 8 The printed circuit board is now free and may be removed to a clean work area If the printed circuit board is being replaced proceed to the section on Installing the Printed Circuit Board page 37 now Otherwise refer to the appropriate section for instructions on nstalling an Option Card page 35 Replacing the EPROM below or Replacing the LCD Display page 36 DigitalFlow GM868 Service Manual 33 Chapter 4 Parts Replacement 4 4 Replacing the EPROM The Model GM868 s User Program is stored on an erasable programmable read only memory EPROM chip The EPROM which i
50. italFlow GS868 Steam Mass Ultrasonic Flowmeter to which this declaration relates are in conformity with the following standards EN 60079 0 2007 EN 60079 1 2004 EN50281 1 1 1998 e 2 G EExd IIC T6 ISSePO3ATEX113 ISSeP B7340 Colfontaine Belgium NoBo 492 EN 61326 1 2006 Class A Table 2 Industrial Locations EN 61326 2 3 2006 EN 61010 1 2012 Overvoltage Category II Other standards Used EN 50014 1997 A1 A2 EN 50018 2000 A1 following the provisions of the 2004 108 EC EMC 2006 95 EC Low Voltage and 94 9 EC ATEX Directives Where products were initially assessed for compliance with the Essential Health and Safety Requirements of the ATEX Directive 94 9 EC using earlier harmonized standards a subsequent review has determined that technical knowledge is unaffected by the current harmonized standards listed above The unit listed above and any ancillary equipment supplied with it do not bear CE marking for the Pressure Equipment Directive as they are supplied in accordance with Article 3 Section 3 sound engineering practices and codes of good workmanship of the Pressure Equipment Directive 97 23 EC for DN 25 A i Perf gil Billerica October 31 2013 Issued Mr Gary Kozinski Certification amp Standards Lead Engineer CE Customer Support Centers U S A The Boston Center 1100 Technology Park Drive Billerica MA 01821 U S A Tel 800 833 9438 toll free 978 437 1000
51. marked pin 1 sides of the connectors face the right side keypad side of the enclosure Note If any leads have come loose from the screw terminals on these connectors refer to Appendix C Optional Enclosures of the Startup Guide for wiring instructions 6 Reconnect the main POWER LEADS to the screw terminals at the rear of the printed circuit board When properly installed the lead colors should be green white and black from left to right as viewed from the front of the enclosure 7 Reinstall all option cards as described earlier in this chapter Insert all external option card connectors at the rear panel of the meter 8 After checking for any loose hardware that may have fallen into the enclosure reinstall the top panel on the meter and secure the panel in place with the four screws previously removed The Model GM868 flowmeter may now be placed back into service Reconnect the main power and refer to Chapter 2 Initial Setup of the Startup Guide and Chapter 1 Calibration of this Service Manual for instructions on properly setting up the meter for accurate flow rate measurements Note Be sure to record the printed circuit board replacement in Appendix A Service Record DigitalFlow GM868 Service Manual 51 Appendix B Optional Enclosures A _ _ _ _ e cas ss no content intended for this page 52 DigitalFlow GM868 Service Manual Appendix B Optional Enclosures 11 82 3
52. ments Note Be sure to record the fuse replacement in Appendix A Service Record 32 DigitalFlow GM868 Service Manual Chapter 4 Parts Replacement 4 3 Removing the Printed Circuit Board All of the remaining maintenance procedures discussed in this chapter require removing the printed circuit board To accomplish this task refer to Figure 8 on page 41 and Figure 9 on page 42 while completing the following tasks 1 Remove the main power to the electronics console WARNING The main power to the Model GM868 must be disconnected before proceeding 2 Open the electronics console For LVD compliant units remove the two mounting screws and lift the clear plastic shroud out of the electronics console Remove the six mounting screws and lift the main aluminum shroud out of the electronics console 3 Disconnect the main power leads and the PC board ground wire from terminal block TB1 on the printed circuit board Remove the electrical connectors from all installed option cards and terminal blocks Disconnect the twisted pair display backlight cable from connector J2 on the left side of the printed circuit board 4 Using a 3 8 in nutdriver or open end wrench remove the three short standoffs along the left side of the main circuit board and the three long standoffs along the right side of the main circuit board 5 While supporting the printed circuit board remove the two screws or standoffs along the bottom edge of the printed c
53. ms arise with the electronics console the flowcell or the transducers Indications of a possible problem include display of an error message on the active display screen e erratic flow readings readings of doubtful accuracy 1 e readings that are not consistent with readings from another flow measuring device connected to the same process If any of the above conditions occurs proceed with the instructions presented in this chapter 3 2 Displaying Diagnostic Parameters The Model GM868 has a built in Diagnostics Menu to aid in the troubleshooting of flowcell transducer and or electrical problems The Diagnostics Menu may only be entered from the Big or Dual measurement mode display See Chapter 2 Displaying Data in the Programming Manual for instructions on setting the display screen to the desired format and enter the Diagnostics Menu as shown below Ch1 label gSITE gt Press the lt 4 or gt keys until the desired channel option appears on the Velocity Ft s option bar Press the appropriate Fx key to select this option 6 95 error codes appear here Note For a 1 Channel Model GM666 the above prompt does not appear and the following prompt is the initial screen Ch1 label gSITE gt Press the lt or gt keys until DIAG appears on the option bar Press the Velocity Ft s appropriate Fx key to select this option 6 95 error codes appear here Note Chl or Ch2 which is shown in parent
54. ntroduction The Model GM868 ultrasonic flowmeter is a reliable easy to maintain instrument When properly installed and operated as described in the Startup Guide the meter provides accurate flow rate measurements with minimal user intervention However if a problem should arise with the electronics console the transducers or the flowcell a built in error code message system greatly simplifies the troubleshooting process All of the possible Model GM868 error code messages are discussed in this chapter along with the possible causes and the recommended actions When an error code is generated it will appear on the active pane of the display screen in the location shown in Figure 7 below Prompt Area Locator Bar Pointer Velocity 6 95 Ch1 E1 Low Signal Option Bar Error Message Figure 7 A Typical Display Screen Note For a 2 Channel Model GM868 the channel number is displayed in front of the error message Only the error message appears with a 1 Channel Model GM666 If an error message appears on the display screen during operation of the Model GM868 refer to the appropriate section of this chapter for instructions on how to proceed DigitalFlow GM868 Service Manual 19 Chapter 2 Error Codes and Screen Messages 2 2 EO Problem Cause Action 2 5 El Problem Cause Action 2 4 E2 Problem Cause Action 2 5 ES Problem Cause Action 20 No Erro
55. nual vii Contents viii DigitalFlow GM868 Service Manual Chapter 1 Calibration Chapter 1 Calibration 1 1 Introduction Calibrating the Model GM868 s analog outputs and inputs is explained in this chapter In addition testing the optional totalizer frequency and alarm relay outputs is discussed The following specific topics are included calibrating Slot 0 6 analog outputs calibrating Slot 1 6 analog inputs calibrating Slot 1 6 RTD inputs testing Slot 1 6 alarm relays testing Slot 1 6 totalizer frequency outputs The Model GM868 electronics console includes six expansion slots for the installation of option cards These slots are numbered 1 6 from right to left In addition every Model GM868 flowmeter includes two built in analog outputs A and B at terminal block I O which is designated as Slot 0 Note Convention in this manual identifies any expansion slot as Slot x where x is a number from 0 6 See Chapter 1 Installation of the Startup Guide for a complete description of the available option cards and the procedures for wiring them 1 2 Menu Map The Calibration Menu is accessed by pressing the CAL key on the keypad Use this menu to calibrate and test the Slot 0 analog outputs as well as to calibrate and test any option cards that are installed in the expansion slots Refer to the menu map in Figure 6 on page 15 as a guide in following the calibration instructions Note The instructions on t
56. oard and option cards See Chapter 1 Installation of the Startup Guide for instructions on proper wiring of the Model GM868 Note For an LVD compliant meter with the clear plastic shroud over the electrical connectors there will be standoffs in the two mounting locations along the bottom edge of the printed circuit board For meters not equipped with this shroud there will be Phillips head screws in these two locations DigitalFlow GM868 Service Manual 37 Chapter 4 Parts Replacement 4 7 Installing the Printed Circuit Board cont 9 For LVD compliant units position the clear plastic LVD shroud over the electrical connections so that the two holes in the shroud align with the standoffs on the printed circuit board Secure the shroud to the standoffs with the two sets of screws and washers 10 After carefully checking for and removing any loose hardware in the enclosure close the electronics console and reconnect the main power to the Model GM868 Note For compliance with the European Union s Low Voltage Directive this unit requires an external power disconnect device such as a switch or circuit breaker The disconnect device must be marked as such clearly visible directly accessible and located within 1 8 m 6 ft of the Model GM868 The power cord is the main disconnect device Before taking measurements with the Model GM868 refer to Chapter 2 Initial Setup of the Startup Guide and Chapter 1 Calibration of the Service
57. ordance with all the appropriate international national and local standard codes and practices and site regulations for flameproof apparatus and in accordance with the instructions contained in the manual Access to the circuitry must not be made during operation 1100 Technology Park Drive Billerica MA 01821 U S A CSS 0013 Rev A Telephone 978 437 1000 or 800 833 9438 August 2014 Sensing House Shannon Free Zone East Shannon County Clare Ireland Telephone 353 61 470200 Certification Safety Statements for GE Infrastructure Products Used in Hazardous Locations August 2014 Special Conditions for Safe Use 1 Consult the manufacturer if dimensional information on any flameproof joint is necessary 2 Follow the manufacturer s instructions to reduce the potential of an electrostatic charging hazard 3 Consult the manufacturer for genuine replacement flange fasteners M10x35 hexagon socket cap screws of ISO 12 9 DIN912 grade steel zinc plated or better with a minimum yield strength of 135 000 psi are acceptable alternatives 4 The sensor body temperature code rating is dependent on the process temperature It is assumed that the external surface of the sensor body will be at worse case equal to the process temperature up to 140 C In all cases the electronics assembly will be marked T6 as it will be locally mounted for process temperatures up to 85 C and will be remotely mounted for process temperatures exceeding 85 C Markings
58. ote Ifyou have installed a new EPROM upon reinitialization the GM868 displays a message Slot x Params appended This message directs users to check the slot error handling on the option cards and appears on power up until you review the parameters in the I O submenu OPTN option 34 DigitalFlow GM868 Service Manual Chapter 4 Parts Replacement 4 5 Installing an Option Card The Model GM868 flowmeter can accommodate up to six option cards The option cards are installed into sockets on the rear of the printed circuit board and they are held in place with a metal bracket A single metal bracket is used to secure all the installed option cards Note Ifthe Model GM868 presently has no option cards installed be sure to purchase the metal mounting bracket along with the first option card To install an option card refer to Figure 9 on page 42 and complete the following steps 1 Remove the printed circuit board as described in a previous section of this chapter 2 Ifone or more option cards are already installed remove the four fasteners that secure the metal bracket to the printed circuit board Lift the metal bracket straight up and away from the printed circuit board Note The fasteners may be either plastic snap rivets or metal hardware in some older meters In either case they may be discarded as new plastic snap rivets will be provided 3 There are six 32 pin option card sockets J41 J46 on the rear of the print
59. proved flameproof design are required for Ex d rated equipment These must be installed according to the manufacturer s instructions Where the cable glands are provided by GE the manufacturer s instructions as supplied to GE will be included in the documentation Unused cable entries must be sealed using a suitably certified threaded plug Modifications to any flameproof enclosure are not permitted The apparatus must be de energized before opening servicing and conducting any routine maintenance Installation shall be in accordance with the installation instructions and the National Electrical Code ANSI NFPA 70 the Canadian Electrical Code C22 1 or IEC EN 60079 14 as applicable The product contains no exposed parts which produce surface temperature infrared electromagnetic ionizing or non electrical dangers The product must not be subjected to mechanical or thermal stresses in excess of those permitted in the certification documentation and the instruction manual The product cannot be repaired by the user It must be replaced by an equivalent certified product Repairs should only be carried out by the manufacturer or by an approved repairer Only trained competent personnel may install operate and maintain the equipment The product is an electrical apparatus and must be installed in the hazardous area in accordance with the requirements of the EC Type Examination Certificate The installation must be carried out in acc
60. put must be calibrated at both the zero point and full scale values After calibrating the inputs their linearity should be tested Calibration of the analog inputs requires the use of a calibrated current source If an independent calibrated current source is not available one of the Slot O analog outputs may be used for the calibration During the analog input calibration the Slot 0 analog output will supply the low reference high reference 4 mA and 20 mA signals at the appropriate times Note Ifa Slot 0 analog output will be used to calibrate the analog inputs make sure that the Slot 0 analog output calibration procedure has already been completed Connect the Slot 0 analog output s or an independent calibrated current source to the analog input s on the option card as shown in Figure 3 below Refer to the menu map in Figure 6 on page 15 as a guide Analog Input Option Card Terminal Block I O Slot 0 Figure 3 Analog Input Calibration Connections 6 DigitalFlow GM868 Service Manual Chapter 1 Calibration 15 Calibrating the Analog Inputs cont For this discussion assume that the option card has been installed in Slot x Note The zero point of the analog input may be set for either 0 mA or 4 mA However the calibration procedure always uses the 4 mA point as the meter
61. r No error condition currently exists This message appears briefly to confirm that the response to another error message has corrected the problem No action is required Low Signal Poor ultrasonic signal strength or the signal exceeds the limits entered via the User Program Poor signal strength may be caused by a defective cable a flowcell problem a defective transducer or a problem in the electronics console A signal that exceeds the programmed limits is probably caused by the entry of an improper value in the SETUP SIGNL submenu of the User Program Using the procedures in Chapter 3 Diagnostics check the components listed above Also check the value programmed into the SETUP SIGNL submenu as described in the Operator Manual Sound Speed Error The sound speed exceeds the limits programmed in the SETUP SIGNL submenu of the User Program The error may be caused by incorrect programming poor flow conditions or poor transducer spacing Compare the measured sound speed to tabulated nominal values for the fluid being used and correct any programming errors Refer to Chapter 3 Diagnostics to correct any flowcell and or transducer problems Velocity Range The velocity exceeds the limits programmed in the SETUP submenu of the User Program This error may be caused by the entry of improper programming data or by poor flow conditions and or excessive turbulence Make sure the actual flow rate is within the programmed limits
62. re directly above the six sockets on the printed circuit board do not install the bracket rotated 180 out of position Secure the metal bracket to the printed circuit board with the four plastic snap rivets provided 7 After checking for any loose hardware that may have fallen into the enclosure reinstall the top panel on the meter and secure the panel in place with the four screws previously removed The Model GM868 flowmeter may now be placed back into service Reconnect the main power and refer to Appendix C Optional Enclosures of the Startup Guide for instructions on wiring the new option card s Note Be sure to record the option card installation in Appendix A Service Record DigitalFlow GM868 Service Manual 47 Appendix B Optional Enclosures B 5 Rack Mount EPROM Replacement The Model GM868 s User Program is stored on an erasable programmable read only memory EPROM chip The EPROM which is designated as component U4 is located on the corner of the printed circuit board just behind the keypad on the front panel EPROM replacement may be required to replace a defective chip or to upgrade to a newer software version To replace the EPROM refer to Figure 11 on page 54 and complete the following steps 1 After disconnecting the main power to the meter remove the top panel from the enclosure by removing the four screws indicated WARNING The main power to the Model GM868 must be disconnected before proceeding
63. re values to help diagnose any future malfunction of the system DigitalFlow GM868 Service Manual 27 Chapter 3 Diagnostics 3 4 Flowcell Problems If preliminary troubleshooting with the Error Code Messages and or the Diagnostic Menu indicates a possible flowcell problem proceed with this section Flowcell problems fall into two categories gas problems e pipe problems Read the following sections carefully to determine if the problem is indeed related to the flowcell If the instructions in this section fail to resolve the problem contact the factory for assistance 3 4 1 Gas Problems Most gas related problems result from a failure to observe the flowmeter system installation instructions as described in the Startup Guide Refer to Chapter 1 Installation of the Startup Guide to correct any installation problems If the physical installation of the system meets the recommended specifications it is possible that the gas itself may be preventing accurate flow rate measurements The gas being measured must meet the following requirements 1 The gas must be homogeneous single phase and relatively clean Although a low level of entrained particles may have little effect on the operation of the Model GM868 excessive amounts of solid or liquid particles will absorb or disperse the ultrasound signals This interference with the ultrasound transmissions through the gas will cause inaccurate flow rate measurements In addition t
64. s designated as component U4 is located in the top left corner of the rear of the printed circuit board see Figure 9 on page 42 EPROM replacement may be required to replace a defective chip or to upgrade to a newer software version To replace the EPROM complete the following steps 1 Remove the printed circuit board as described in a previous section of this chapter 2 Place the printed circuit board face down on a clean flat surface Locate the EPROM socket in the top left corner of the board CAUTION The EPROM is easily damaged by static electricity Before handling the new chip touch a grounded metal object to discharge any built up static electricity and avoid touching the leads on the side of the chip 3 Using a chip puller remove the EPROM from its socket If a chip puller is unavailable a straightened paper clip may be used in the notches at the upper right and lower left corners of the socket Gently pry the EPROM up a little at a time at each notch until it comes free 4 Make sure that the beveled corner on the new EPROM is aligned with the beveled corner of the socket and place the EPROM into the socket 5 By applying equal pressure on all four corners gently press the EPROM into the socket until it is fully seated Do not strike the EPROM or apply excessive force during this procedure Complete the EPROM replacement by proceeding to the Installing the Printed Circuit Board section of this chapter page 37 N
65. t it is field replaceable when necessary To replace the LCD display refer to Figure 11 on page 54 and complete the following steps 1 After disconnecting the main power to the meter remove the top panel from the enclosure by removing the four screws indicated WARNING The main power to the Model GM868 must be disconnected before proceeding 2 Using a 3 16 in nutdriver remove the four nut washer sets that secure the display shroud to the inside of the front panel Pull the display shroud off its mounting studs 3 Using a 1 4 nutdriver remove the four standoffs that secure the LCD display assembly to the front panel Pull the LCD display assembly off its mounting studs 4 Place the new display in the enclosure and replace the circuit board connections of the data and power cables of the old display with those of the new display Be sure to orient the new cables in the same way as the old ones when making the connections to the printed circuit board Remove and discard the old LCD display 5 Place the new LCD display assembly over the mounting studs on the front panel and fasten it in place with the four standoffs Make sure that the LCD display assembly is oriented with the cables pointing toward the left side away from the keypad of the meter CAUTION Do not overtighten the standoffs or the display assembly may be damaged 6 Position the LCD display cables between the two mounting studs and install the display shroud ov
66. the Startup Guide they will not be repeated here All other messages are listed in Table 2 below Table 2 Screen Messages II T Meng Power Up Messages The backup battery that powers the non volatile RAM has failed Backup Battery FAIL Contact the factory Backup Battery OK The backup battery that powers the non volatile RAM has passed DSP Processor OK The DSP digital signal processor has passed The DSP digital signal processor RAM has failed Contact DSP RAM Failed the factory DSP RAM OK The DSP digital signal processor RAM has passed Record the EPROM sum at the initial power up and periodically EPROM sum XXXX thereafter The NVR non volatile RAM was automatically initialized due to FRIGID_INIT Executed a memory fault Contact the factory NVR FAIL The non volatile RAM has failed Contact the factory NVR OK The non volatile RAM has passed Measurement Mode Messages This message may appear during one of the following tasks 1 clearing a log there are no more logs to clear logging data user has hit ENT instead of selecting an old log or entering a new name All Logs Cleared hit key printing a log there are no logs to print displaying a log there are no logs to display Hit any key to resume taking measurements This message may appear during one of the following tasks 1 saving a new site a new site name was not entered or overwrite existing site was not selecte
67. the outputs connect a frequency counter to the card s terminal block as shown in Figure 5 below Refer to the menu map in Figure 6 on page 15 as a guide Terminal Block Option Card Frequency Counter Figure 5 Frequency Counter Connections For this discussion assume that the option card has been installed in Slot x 1 8 1 Accessing the Calibration Menu 1 Press the CAL key to enter the Calibration Program 2 Press Fx to calibrate the desired slot The option bar will include a slot listing for each installed option card 3 Press F1 F4 to select output A B C or D respectively 1 8 2 Entering Frequency 4 Enteranew frequency in the range of 1 10 000 Hz and press the ENT key Verify that the frequency counter reads the correct value DigitalFlow GM868 Service Manual 13 Chapter 1 Calibration 1 8 3 Entering Pulse Number 5 Enter a new frequency in the range of 1 10 000 Hz and press the ENT key Verify that the frequency counter reads the correct value 6 Repeat Steps 3 4 and 5 to test all four of the frequency totalizer outputs Ifany of the outputs fails to pass the test contact the factory for assistance Procedure Options You have completed testing the totalizer frequency outputs Do one of the following To calibrate test additional slots press F4 EXIT and proceed to the appropr
68. ucer problems 2 9 E7 Analog Out Error Problem Cause Action The current in the analog output circuit exceeds the limits for the analog output port The output load exceeds the specified limits for the analog output port Make sure the output load is lt 550 ohms for the Slot 0 analog outputs or is lt 1000 ohms for an analog outputs option card slots 1 6 2 10 E8 Temp In Problem Cause Action 2 11 E9 Problem Cause Action This message indicates a temperature input error The temperature exceeds the specified limits for the analog inputs option card Check the temperature transmitter and the connecting cable Refer to Chapter 1 Calibration and recalibrate the analog inputs on the option card Press In This message indicates a pressure input error The pressure exceeds the specified limits for the analog inputs option card Check the pressure transmitter and the connecting cable Refer to Chapter 1 Calibration and recalibrate the analog inputs on the option card DigitalFlow GM868 Service Manual 21 Chapter 2 Error Codes and Screen Messages 2 12 E10 Special Input Problem This message indicates a special input error Cause The special input exceeds the specified limits for the analog inputs option card Action Check the special transmitter and the connecting cable Refer to Chapter 1 Calibration and recalibrate the analog inputs on the option card 2 13 E11 Not Used This
69. uit board Then install only the top and bottom short standoffs on the left side of the printed circuit board 4 Insert the free end of the green grounding strap between the printed circuit board and the middle standoff beneath the left side of the board Making sure to capture the grounding strap lug between the printed circuit board and the standoff beneath it install the remaining short standoff on the left side of the printed circuit board Securely tighten all eight standoffs and or screws IMPORTANT Correctly installing the grounding strap may require some patience but resist the temptation to place the grounding strap on top of the printed circuit board 5 Connect the twisted pair backlight cable to socket J2 on the left edge of the printed circuit board This plug is polarized so that it can only be installed in the proper orientation with the black wire above the red wire 6 Check for and remove any loose hardware that may have fallen into the electronics console during the maintenance procedure 7 Place the main shroud over the six upper standoffs on the printed circuit board Making sure that the shroud is oriented with the wiring diagram label upright fasten the shroud to the standoffs with the six sets of screws and washers 8 Reconnect the power line wires and the PC board ground wire to terminal block TB1 on the printed circuit board Plug all other electrical connectors into the appropriate sockets on the printed circuit b
70. ur onte Mettre de e eta le t de oo 4 Calibrating the Analog INPUTS na een d ET T E E li t bt etd DU EL tidy 6 1 5 1 Accessing the Calibration Menu dp a Esos 7 Wee CNY Bonus cs ipii Cm TET 8 IGS OMAGH Options F2 aedes uto NA 8 Eo Oil Nee EE O REE T EE CE NR PEERS RM 8 Tie mA ODIO e Us eee eee uero ed tm E rotes ae o ee ea A eee ica Er lica p oe 8 Calibrating the RED UN PULS ei e 2 a ea adt a t o 9 1 6 1 Accessing the Calibration Menu doc caia ma i ee eco E OR eec ob Pu Rd ume ea E 9 TG 2 PROD OPUON s eau cc tte tp be Ue tp a a etii 9 1 520 SEP Temperdtbupe ss cec bo a 9 1 6 2b Slope Point Temperatures copita ridad tenes 9 163 N meroption AF2 ek alia di etos hi date A durdse c bee hale 10 ESA AMA A da Linie cec di nieve 10 16 30 Slope NUITS ova zece santo e D SEE ae nai 3 ip 10 Testing tbe ATE e ou ores tm ers ctos A dL Uca V ist e ata a a Sea A 11 1 71 Aecessing the Calibration Ve I sos cue out htt aa em ata si tie tud rome ba v dames OE 11 Testing the totalizando Mot 13 1 8 1 Accessing the Calibration Md 3 ii A de L O 13 1 8 2 Entering Frequency de e Dota Lucis Alba ae De a t A 13 1 8 5 Entering Pulse NUM BE e sea 00 nt a id do eto ae 14 DigitalFlow GM868 Service Manual V Contents Chapter 2 Error Codes and Screen Messages 2l A A A MM OM IN EE NE 19 2 25 VEO odd MT 20 23 E o o Lir eae A 20 Z4 E2 Sound Speed pps A A IA te a eM e prier a 20 Z5 ES NEOCRON GO a e e o torus Mo Dl e A DUE E 20 2 5 EA SNA O1
71. uropean Union 5 Low Voltage Directive this unit requires an external power disconnect device such as a switch or circuit breaker The disconnect device must be marked as such clearly visible directly accessible and located within 1 8 m 6 ft of the Model GM868 B 2 Rack Mount Enclosure Refer to Figure 10 on page 53 and Figure 11 on page 54 for the location of the relevant components while completing the following procedures If the top panel of the meter is accessible service may be performed without removing the meter from the rack Otherwise disconnect all rear panel electrical connections and remove the meter from the rack before proceeding IMPORTANT Keep a detailed record of all service procedures in Appendix A Service Record This record may prove very helpful in diagnosing any future problems DigitalFlow GM868 Service Manual 45 Appendix B Optional Enclosures B 3 Rack Mount Fuse Replacement If it has been determined that the fuse in the Model GM868 requires replacement refer to Figure 10 on page 53 and Figure 11 on page 54 and complete the following steps 1 On the rear panel of the meter set the power switch to the OFF position and pull the power cord out of its receptacle WARNING The main power to the Model GM868 must be disconnected before proceeding 2 Locate the black plastic fuse cover on the back panel at the bottom of the power cord receptacle and pull it straight out 3 Replace the defective
72. will extrapolate this value to obtain the 0 mA point 1 5 1 Accessing the Calibration Menu 1 Press the CAL key to enter the Calibration Program 2 Press Fx to calibrate the desired slot The option bar will include a slot listing for each installed option card 3 Press Fx to select the desired input The procedure for calibrating Input A is identical to that for calibrating Input B However when calibrating Input B be sure a calibrated current source is connected to the appropriate pins on the terminal block See Figure 3 on the previous page for the correct pin numbers To calibrate a 0 4 20 mA input card see the section below Note To calibrate an RTD input card refer to page 9 4 Press F1 F4 to select the reference point to be calibrated Do one of the following Ifyou selected F1 aLOW proceed to aLOW Option on the next page Ifyou selected F2 aHIGH proceed to aHIGH Option on the next page Ifyou selected F3 4 mA proceed to 4 mA Option on the next page Ifyou selected F4 20 mA proceed to 20 mA Option on the next page DigitalFlow GM868 Service Manual 7 Chapter 1 Calibration 1 5 2 aLOW Option F1 1 2 3 Enter the low reference value and press the ENT key Press F1 to store the current low reference value or press F2 to cancel the entry In either case the ANALOG INPUT prompt will reappear Press F2 to proceed to the next section 1 5 3 aHIGH Opt

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