Transmission Line Loss Calculation
Contents
1. 21 JEMStar Multifunction Electricity Meter Other errors during communications Most error messages result from unexpected problems during communications Usually these problems are transient and retrying communications will work If communication errors become frequent the cable you are using may be defective JEMRead Software Error Message Could not connect to meter Select Connect from the Meter Communication menu Click on the COM port you are using and make sure the baud rate is set the same as the JEMStar meter If not click the Setup button and verify your connection type baud rate and address is correct Click OK to return to the first screen and then select the Connect button If you get another error message then you did not select an open port on your system Try to select different ports until you find one that works If you are still unable to establish communications contact AMETEK for assistance The meter is not responding Make sure that the JEMStar is connected to the selected serial port Check your cable connections and make sure the meter is powered by checking the LCD display on the front plate Contact AMETEK for assistance Other errors during communications Most error messages result from unexpected problems during communications Usually these problems are transient and retrying communications will work If communication errors become frequent the cable you are using may be defective My RS2. JEMSIAR Digital Multifunction Electricity Meter Application Notes Publication 1083 608 Rev A May 2002 AMETEK Power Instruments Tel 800 881 4156 255 N Union Street Fax 585 238 4945 Rochester New York 14605 Web www rochester com Important Safety Notice Installation operation and maintenance of this product can present potentially hazardous conditions if safety procedures are not followed To ensure that this product is used safely it is important that you e Review understand and observe all safety notices and recommendations within this manual e Review your company safety procedures for meter installation and service DANGER Hazardous voltages are present during normal servicing of this device that can cause severe injury or death These voltages are present throughout the utility s potential transformer PT and current transformer CT circuits and the meter s connection terminals Only qualified properly trained personnel should perform installation and servicing on this equipment November 2000 AMETEK Inc all rights reserved Scientific Columbus is a trademark of AMETEK Inc JEM is a registered trademark of AMETEK Inc MicroJoule II is a registered trademark of AMETEK Inc SC 30 is a registered trademark of AMETEK Inc JEMStar JEMWare JEMRead are trademarks of AMETEK Inc MV 90 is a trademark of Itron Energy Information Systems Inc Windows is a trademark of Microsoft Corp
3. MODBUS is a trademark of Schneider Systems Inc Table of Contents Application NOLES fetes eect eet lhe he IIo h ah tea sel ee etka 1 Introduction ashsa sess cea vs deve te vsesesete dane ety dem iier eE EE e aE Eii aiai cee tienda Mavelcas Mis 1 Transmission Line Loss Calculation JEMStar Transformer and Line Loss Compensation Formulae and Technical Description E cay ck svienea ted cau anta dana E E ec ua cs eas A 2 Notes of BPR Billing Period Reset ast yics senate eden aieaiceesnetisa ean ala nde ahaaieranebiieeeks 14 JEMStar Analog Output Verification as fice sccsiegicaasheendeeddcatanuseeate aahnaedsencsaiets 14 External Control of Load Profile Recording 20 0 0 cccceccceceeceeseeceseeeeeceeeeeessecnaeeeteenaees 19 Tro bl sh otmg Tipnut aenar Rna AE TE A REE a ATSDR 21 General Meter CSAs esc 5 cxcgasdsanst ann a a A Moses ARTAR 21 JEM Ware SoftWaTe noskich icenian a a a e a ia a anemone 21 INAY B RAET aTa B3 u AAEE E EE E E EE EE ETE ES 22 JEMStar Application Notes INTRODUCTION The JEMStar meter is a very user friendly meter with most features and operating functions being self explanatory Once you become familiar with the basic operation of the front panel pushbuttons and the simple Windows software menus you can read configure and create reports from the data collected by the meter Hardware and software instruction manuals and a Windows Help system are included to assist you with detailed explanations of the exte
4. 66 x 24 945 7 78 191 6 for each phase Line watts loss when meter is running at nominal test current calculated for each of 3 transformer phases LWCULINE phase 10 x 200 x 0 05 200 000 for each phase Total transformer and line losses calculated for each of 3 transformer phases LWCU phase 78 191 6 2 000 000 278 191 6 for each phase Percent Loss calculated for each of 3 transformer phases LWCUphase 100 x 278 191 6 120 x 66 x 10 x 200 1 76 for each phase Sum the LWCUphase results and apportion 1 3 of the system losses LWCU vg to each of the 3 meter elements LWCU vg 278 191 6 278 191 6 278 191 6 0 3 278 191 6 Calculate TLC coefficient calculated for each of 3 meter elements Kwcu 278 191 6 10 x 200 0 06955 for each meter element FE VARS LOSS Kvre Transformer test VA losses calculated for each of 3 transformer phases NLVAphase 0 353 x 9 000 000 100 31 770 for each phase Transformer test VAR losses calculated for each of 3 transformer phases NLVAR phase sqrt 3 1 770 2 _ 7961 3 30 756 3 for each phase Transformer iron VARs loss when meter is running at nominal voltage calculated for each of 3 transformer phases LVFEphase 120 x 66 7967 x 30 756 3 30 036 9 for each phase Percent Loss calculated for each of 3 transformer phases 11 JEMStar Multifunction Electricity Meter LVFEphase 100 x 30 036 9 120 x 66x 10 x 200 0 19
5. each internal meter element Forms 6 and 9 3 of the system losses are apportioned to each of the 3 meter elements Form 5 1 2 of the system losses are apportioned to each of the 2 meter elements Form 8 of the system copper watt and VAR losses are apportioned to each of the 3 internal meter elements Approximately 73 of the system iron watt and VAR losses are apportioned to element A with the remaining iron losses split evenly between elements B and C This compensates for the fact that phase A measures a voltage that is 208 120 higher than phases JEMStar Multifunction Electricity Meter B and C and for the fact that none of the elements directly measure the line to line transformer voltage 4 When the TLC feature is Enabled in the JEMWare configuration these losses will be added to or subtracted from the JEMStar per phase watt and VAR readings Adding or subtracting depends on the configuration settings The total 3 phase system losses are simply the sum of the three per phase losses and are added to or subtracted from the polyphase watt and VAR reading JEMStar Application Notes D TYPICAL EXAMPLE CALCULATIONS The following equations illustrate the TLC coefficient calculations for a FORM 9 meter a FE WATTS LOSS Kwre Transformer iron watts loss when meter is running at nominal voltage calculated for each of 3 transformer phases LWFEphase Veer x PTratio Vr x NLW Percent Loss calc
6. recorded by the meter was consumed while some externally controlled period such as a generator shutdown was in effect To date users have been able to perform this function with register data by using the TOU Rate Override input The user configures a Watthour register associated with the TOU Override rate and then applies a signal to the TOU Rate Override contact input when the external condition is present This is sufficient in some cases but some users need Load Profile data that is segregated in the same way The solution is to configure Load Profile channels to record only when the TOU Rate Override input is active Using the TOU Rate Override input to mark the external condition allows both registers and Load Profile to collect the same data which can be compared later JEMWare can be used to configure any Load Profile channel to record when the TOU Rate Override contact input is ON Note The TOU Rate Override input does not affect interval timing in any way It will only gate the collection of measurements in configured Load Profile channels Load Profile channels configured to record only during TOU Rate Override are not associated with a given TOU rate For example If the meter is configured to use Rate C as the TOU Override rate and Rate C also appears in the normal TOU schedule the selected Load Profile channels record only while the TOU Rate Override input is on Average Instantaneous Load Profile channels that are configured
7. 3 transformer phases NLVAR hase Sqrt NLVA phase NLW Transformer iron VARs loss when meter is running at nominal voltage calculated for each of 3 transformer phases LVFEphase VMETER X PTraTIO Vy X NLVAR phase Percent Loss calculated for each of 3 transformer phases YLVFEphase 100 x LVFEphase Veter X PTratio X Imerer X CTratio Sum the LVFEpnase results and apportion 1 3 of the system losses LVFEayg to each of the 3 meter elements Calculate TLC coefficient calculated for each of 3 meter elements K vee LVFEayg VMETER X PTpatio d CU VARS LOSS Kycu JEMStar Application Notes Transformer test VA losses calculated for each of 3 transformer phases FLVAphase YoI x VAr 100 Transformer test VAR losses calculated for each of 3 transformer phases FLVAR phase Sqrt FLVA phase FLW Transformer copper VARs loss when meter is running at nominal test current calculated for each of 3 transformer phases LVCUphase Imerer X CTratio In x FLVAR phase Percent Loss calculated for each of 3 transformer phases LVCUphase 100 x LVCUphase Vmeter X PTratio X IMETER X CTratio Sum the LVCUphase results and apportion 1 3 of the system losses LVCUa yg to each of the 3 meter elements Calculate TLC coefficient calculated for each of 3 meter elements Kycu LVCUavg IMeter X CTratio e NUMERICAL EXAMPLE Form 9 PER PHASE TRANSFORMER AND LINE LOSS DA
8. 485 network does not recognize all the meters in the string Each JEMStar in the string must have a unique address assigned using JEMRead software You will need to configure the addresses individually before you connect the RS 485 network cabling Refer to the JemRead instruction manual 1083 601 for full details 22
9. TA Phase A Phase B Phase C RATED VOLT AMPS VAr 9 000 000 9 000 000 9 000 000 RATED VOLTAGE Vr 7967 7967 7967 FE LOSS NO LOAD NLW 7961 3 7961 3 7961 3 CU LOSS FULL LOAD FLW 24 945 7 24 945 7 24 945 7 EXCITING CURRENT EC_ 0 353 0 353 0 353 IMPEDANCE I 14 49 14 49 14 49 LINE RESISTANCE ohms Ry 0 05 0 05 0 05 JEMStar Multifunction Electricity Meter METER AND INSTRUMENT TRANSFORMER DATA PT RATIO PTRatio 66 1 CT RATIO CT Ratio 200 1 NOMINAL METER VOLTAGE Veter 120 volts METER TEST CURRENT IMETER 10 amps FE WATTS LOSS Kwre Transformer iron watts loss when meter is running at nominal voltage calculated for each of 3 transformer phases LWFE phase 120 x 66 7967 x 7961 3 7867 6 for each phase Percent Loss calculated for each of 3 transformer phases LWFEphase 100 x 7867 6 120 x 66 x 10 x 200 0 05 for each phase Sum the LWFEphase results and apportion 1 3 of the system losses LWFE yg to each of the 3 meter elements LWFEavg 7867 6 7867 6 7867 6 3 7867 6 Calculate TLC coefficient calculated for each of 3 meter elements Kwee 7867 6 120 x 66 0 00012543 for each meter element CU WATTS LOSS Kwcu Calculate transformer test current Ir 9 000 000 7967 1129 66 Transformer copper watts loss when meter is running at nominal test current calculated for each of 3 transformer phases 10 JEMStar Application Notes Transformer LWCUT Xphase 10 x 200 1129
10. TAR CALCULATION OF LOSS WATTS AND VARS Equations for each meter element IRON LOSS WATTS Kwer x V COPPER LOSS WATTS Kweux I IRON LOSS VARS Kyrr x V COPPER LOSS VARS Kycu x I Example If the PT and CT secondaries for each phase are 125 volts and 5 amps respectively Scale by PT and CT ratios done within JEMSTAR V 125 x 66 8250 volts I 5 x 200 1000 amps Calculate losses for each element IRON LOSS WATTS 0 00012543 x 8250 8537 watts COPPER LOSS WATTS 0 06955 x 1000 69 550 watts IRON LOSS VARS 7 634 x 10 x 8250 35 365 VARs COPPER LOSS VARS 1 02173 x 10007 1 021 730 VARs 13 JEMStar Multifunction Electricity Meter NOTES ON BPR BILLING PERIOD RESET CAUTION Data can be lost if it is not downloaded and saved prior to performing a BPR command The BPR function is used to clear the storage registers in a JEMStar meter This operation can be performed manually from the meter s front panel user interface or via JEMRead or JEMWare software commands In addition the user can program an Automatic Schedule in JEMRead to perform a BPR as a regular occurrence Make sure that your data has been saved before a BPR is performed JEMSTAR ANALOG OUTPUT VERIFICATION JEMStar can include an optional feature that consists of three analog output channels All three channels are defined at the time of manufacture for either 0 1 mA or 4 20 mA outputs Each of the output channels can be configured to re
11. for each phase Sum the LVFEpnase results and apportion 1 3 of the system losses LVFEayg to each of the 3 meter elements LVFEavg 30 036 9 30 036 9 30 036 9 3 30 036 9 Calculate TLC coefficient calculated for each of 3 meter elements Kvre 30 036 9 120 x 66 7 634 x 10 for each meter element CU VARS LOSS Kycu Transformer test VA losses calculated for each of 3 transformer phases FLVA phase 14 49 x 9 000 000 100 1 304 100 for each phase Transformer test VAR losses calculated for each of 3 transformer phases FLVAR phase sqrt 1 304 100 24 945 7 1 303 861 for each phase Transformer copper VARs loss when meter is running at nominal test current calculated for each of 3 transformer phases LVCUphase 10 x 200 1129 66 x 1 303 861 4 086 917 for each phase Percent Loss calculated for each of 3 transformer phases LVCUphase 100 x 4 086 917 120 x 66 x 10 x 200 25 80 for each phase Sum the LVCUphase results and apportion 1 3 of the system losses LVCU yg to each of the 3 meter elements LVCUaye 4 086 917 4 086 917 4 086 917 3 4 086 917 Calculate TLC coefficient calculated for each of 3 meter elements Kycu 4 086 917 10 x 200 1 02173 for each meter element 12 JEMStar Application Notes TLC COEFFICIENT SUMMARY For each Form 9 meter element A B and C Kwre 0 00012543 Kwcu 0 06955 Kvre 7 634 x 10 Kycu 1 02173 JEMS
12. for TOU Rate Override are averaged over the period that the TOU Rate Override input is on For example with a constant 1000 watts applied to the meter and an Average Instantaneous Watt load profile channel if the TOU Rate Override input is active for one half of an interval the final value recorded in that interval will be 1000 watts not 500 watts If the TOU Rate Override input stays off for the entire interval the channel will record 0 An exception to this is Average Power Factor which resets to 1 0 at the beginning of an interval and will remain there unless some actual measurements are collected JEMStar can be optionally configured to only record Load Profile data during externally triggered periods This can be user selected on a per channel basis which means that some channels can record constantly and some can record upon command from an external source JEMWare can be used to configure any Load Profile channel to record when the TOU Rate Override contact input is ON To configure this operation in JEMWare 1 Go to the Load Profile menu and either Add a new LP channel or highlight an existing one to Edit 2 In the setup screen choose Records During TOU Override Only Choose OK 19 JEMStar Multifunction Electricity Meter 3 Go to the Contact Input Output menu and set one of the two Input channels for TOU Rate Override 4 Apply a signal to the Contact Input to begin LP recording on the designated channel N
13. ge connect a load resistor to Aout 1 as follows 0 1 mA Outputs 4 20 mA Outputs 1K 250 ohm Aout 1 di 0 01 j Sine 0 01 z 7 External Source 0 1 mA Output Connection 4 20 mA Output Connection 17 JEMStar Multifunction Electricity Meter Step 6 Apply 80 volts to the Phase A meter terminals Repeatedly press the front panel READ pushbutton to scroll to the display register you assigned for Phase A volts in Step 2 and then press SET to hold the display at this register Adjust the source voltage to read 80 00 0 02 volts on the LCD display Measure the output voltage across the load resistor and verify that the analog output is as follows Range Reading 0 ImA 0 00 V 0 001V 0 1 4 20mA 1 00 V 0 004V_ 0 1 Step 7 Increase the source voltage to read 120 00 0 02 volts on the LCD display Measure the output voltage across the load resistor and verify that the analog output is as follows Range Reading 0 ImA 1 00 V 0 001V 0 1 4 20mA 5 00 V 0 004V_ 0 1 Repeat Steps 5 6 and 7 for the other two analog outputs at Aout 2 and Aout 3 18 JEMStar Application Notes EXTERNAL CONTROL OF LOAD PROFILE RECORDING JEMStar users have requested a method to distinguish Load Profile data that was collected during externally recognized asynchronous periods In other words users want to be able to tell if energy
14. n the JEMWare CONSTANTS page of the Loss Compensation screen and are scaled for the JEMWare internal circuitry and mathematical requirements The values calculated in this example are not scaled and will not be equivalent to those displayed by JEMWare C JEMWare CALCULATION OF TLC COEFFICIENTS First we must define a few terms used in the following description of TLC coefficient calculation Transformer phase refers in this description to an individual leg of a multi phase transformer or a single transformer of a multi phase bank Meter element refers to an internal meter input consisting of a current and voltage input pair It is important to note for purposes of TLC that for certain meter forms there is not a direct correlation between transformer phases and meter elements Forms 6 and 9 Three transformer phases A B C measured with three internal meter elements A B C Form 6 is a 2 2 element meter but the missing phase voltage is reconstructed digitally The meter elements directly measure the transformer phase voltages and currents Form 8 Three transformer phases A B C measured with three internal meter elements A B C However because of the delta configuration the meter elements measure transformer line currents not phase currents and because the JEMStar Application Notes voltages are measured with respect to neutral none of the meter voltages correspond directly to the voltage across the transformer secondar
15. n to a single device However in a two wire RS 485 link data flow is bi directional and half duplex data is never transmitted and received at the same time RS 485 lines should be connected in a daisy chain configuration with a 120 ohm termination resistor jumpered in at each end of the chain Refer to the Maintenance section of the JEMStar User Manual 1083 600 for jumper instructions JEMWare Software Error Message Could not connect to meter Select Connect from the Meter Communication menu Click on the COM port you are using and make sure the baud rate is set the same as the JEMStar meter If not click the Setup button and verify your connection type baud rate and address is correct Click OK to return to the first screen and then select the Connect button If you get another error message then you did not select an open port on your system Try to select different ports until you find one that works If you are still unable to establish communications contact AMETEK for assistance Error Message Could not send command Process aborted If this message appears when you attempt to Write or Read configuration data check to see if you are connected to the correct COM port on your computer The meter is not responding Make sure that the JEMStar is connected to the selected serial port Check your cable connections and make sure the meter is powered by checking the LCD display on the front plate Contact AMETEK for assistance
16. ns ratio Where R resistance to be entered into JEMWare TLC screen in ohms Primary Line Resistance primary side line resistance in ohms Turns ratio main transformer turns ratio primary turns secondary turns JEMSTAR TRANSFORMER AND LINE LOSS COMPENSATION FORMULAE AND TECHNICAL DESCRIPTION The following describes the methods and equations used by the JEMStar meter and JEM Ware software to implement transformer and line loss compensation An actual example using a Form 9 meter is illustrated at the end of the discussion A DATA REQUIRED FOR TRANSFORMER AND LINE LOSS COMPUTATION TRANSFORMER AND LINE DATA JEM Ware allows single phase or multi phase computation of TLC For the purposes of this example each value is a transformer per phase value As described in JEMWare manual 1083 602 the following parameters must be entered into the Loss Compensation window item 7 is only required if computing Line Loss 1 RATED VOLT AMPS VArt 2 RATED VOLTAGE Vr 3 FELOSS NOLOAD NLW JEMStar Application Notes 4 CU LOSS FULL LOAD FLW 5 EXCITING CURRENT EC 6 IMPEDANCE I 7 LINE RESISTANCE RL NOTES 1 Form 6 8 9 amp Form 5 3 wire delta and 3 wire Y In the case of three phase transformer and line loss data divide the total three phase data values for items 1 3 4 and 7 by three to enter transformer data on a per phase basis Data values for items 2 5 and 6 remain the same whether using three phase total or individual
17. nsive operating features of JEMStar This document is intended to assist the advanced user by providing some insight into the application of JEMStar s features The topics and suggestions contained herein represent a collection of user s requests and experiences with the meter We hope that this will provide a forum to expand your knowledge and at the same time keep us in touch with your metering needs We welcome your thoughts and requests and we would be interested in discussing the future of utility metering with you Our toll free 800 number listed on the cover is available for your use JEMStar Multifunction Electricity Meter TRANSMISSION LINE LOSS CALCULATION It is possible to perform line loss compensation for line losses on the primary side of the main transformer You should be familiar with JEMWare operation and the use of the Transformer Loss Compensation TLC feature If not review this section in the JEM Ware manual publication 1083 602 before proceeding Presently the line resistance entered in the JEMWare TLC window is applied to the primary side of the PT and CT the secondary side of the main transformer To perform line loss compensation on the primary side of the main transformer do the following In the JEMWare TLC window enter the primary line resistance divided by the square of the transformer turns ratio where the turns ratio is given as primary turns secondary turns R Primary Line Resistance tur
18. otes e The TOU Rate Override input does not affect interval timing in any way It will only gate the collection of measurements in configured Load Profile channels e Load Profile channels configured to record only during TOU Rate Override are not associated with a given TOU rate For example If the meter is configured to use Rate C as the TOU Override rate and Rate C also appears in the normal TOU schedule the selected Load Profile channels record only while the TOU Rate Override input is on 20 JEMStar Application Notes TROUBLESHOOTING TIPS General Meter Usage The E status flag is lit on the LCD display This indicates that the microprocessor has experienced a problem during normal functioning The problem may have been caused by an external operation or simply during normal processor activity Once activated the Error flag will lock in and remain on until reset therefore the anomaly may or may not still exist Check to ensure that the power supply voltage is within its operating range To reset the indicator turn the power off and then back on again If the flag lights immediately the problem still exists and requires further investigation Ifthe flag stays out the problem has cleared itself and no further attention should be necessary The RS 4835 serial data output does not work properly The serial port on JEMStar can be configured for either RS 232C or RS 485 RS 232C is a straightforward cable connectio
19. phase calculations 2 Form 5 open delta and network In the case of two phase transformer and line loss data divide total two phase data values for items 1 3 4 and 7 by two to enter transformer data on a per phase phases A and C only basis Data values for items 2 5 and 6 remain the same whether using three phase total or individual phase calculations 3 Iron losses are related to the transformer phase voltage Copper losses are related to the transformer phase current METER AND INSTRUMENT TRANSFORMER DATA The following parameters are used in the computation of TLC coefficients PT RATIO PTRatio from JEMWare Primary Config screen CT RATIO CT ratio from JEMWare Primary Config screen NOMINAL METER VOLTAGE Verter from JEMWare Primary Config screen METER TEST CURRENT Imerer from JEMWare Loss Compensation screen JEMStar Multifunction Electricity Meter B TLC EQUATIONS JEMStar calculates loss watts and VARs based on the following formulas IRON LOSS WATTS Kwre x V COPPER LOSS WATTS Kwcu x I IRON LOSS VARS Kyre x V COPPER LOSS VARS Kycu x Where V is the voltage across and T is the current through each phase of the transformer Kwre Kwcu Kvre Kvcu are coefficients calculated by JEMWare and downloaded to the JEMStar meter during configuration Each meter element per phase watt and VAR reading is compensated individually NOTE The values for these coefficients are displayed o
20. present any instantaneous quantity measured by the meter watts VARs volts amps etc This procedure uses Volts as the test input because it is the simplest quantity to regulate precisely Re calibration of analog outputs must be done at the factory only However the user can verify the accuracy of the outputs by following this procedure If a problem is found please contact AMETEK s technical support group Test Setup The meter under test should be installed in a test fixture so that the input voltage can be adjusted during the test In addition the outer globe must be removed to allow access to the front panel pushbuttons and the Security keys must be installed See the Maintenance section of User Manual 1083 600 for this procedure You will need the following e Stable AC voltage source capable of 80 to 120 Vrms at 10VA e 1K ohm resistor 0 01 if testing a meter with 0 1mA outputs e 250 ohm resistor 0 01 if testing a meter with 4 20mA outputs Step 1 Using JEMWare Meter Settings Analog Outputs menu configure all three analog outputs for the following Measured Quantity Volts Maximum 120 Minimum 80 Phase A 14 JEMStar Application Notes Output Type Click the range that was factory set for your meter Analog Outputs g s CN o C Poy ae LK f canes He Step 2 In JEMWare Meter Settings Display Registers Add menu add a Normal display register as follows ID Any unused registe
21. r number 25 shown in the example Register Category Register Register Type Instantaneous Base Quantity Volts Phase Phase A Storage Type Working Number of Digits 5 Decimal Position 2 15 JEMStar Multifunction Electricity Meter Step 3 Download this configuration to the meter to be tested Refer to the JEMWare instruction manual 1083 602 for further details about downloading new configurations Step 4 Connect a stable AC voltage source to Phase A volts Refer to the connection diagrams in the JEMStar User Manual 1083 600 for your meter Form Use a voltage source capable of 80 to 120 volts with a minimum 10VA For a switchboard meter apply power to Aux Power as well 16 JEMStar Application Notes Step 5 Connect a load resistor to the meter s analog outputs For the S Base and A Base meter styles JEMStar analog output connections are provided via a 3 foot multi conductor cable The wire colors are as follows S amp A Base Analog Output Connections Color Signal Wht Red Brn Aout Wht Red Grn Aout Wht Org Brn Aout 2 Wht Org Grn Aout 2 Wht Blk Aout 3 Wht Gry Aout 3 For Switchboard style meters the connections are provided on rear mounted terminal blocks Switchboard Analog Output Connections Terminal Signal 8 Aout 1 7 Aout 1 6 Aout 2 5 Aout 2 4 Aout 3 3 Aout 3 Depending upon your meter s output ran
22. ulated for each of 3 transformer phases L WE E hase 100 X L W F E hase V METER X F Tratio X IMETER X p p CTratio Sum the LWFEphase results and apportion 1 3 of the system losses LWFE yg to each of the 3 meter elements Calculate TLC coefficient calculated for each of 3 meter elements Kwre LWFEavg Vaeter X PTRatio CU WATTS LOSS Kwcu Calculate transformer test current Ir VAr Vr Transformer copper watts loss when meter is running at nominal test current calculated for each of 3 transformer phases Transformer LWCUTX phase meter X CT ratio It x FLW Line watts loss when meter is running at nominal test current calculated for each of 3 transformer phases LWCULINE phase Imeter X CTratio x Rr Total transformer and line losses calculated for each of 3 transformer phases JEMStar Multifunction Electricity Meter LWCUphase LWCUT Xphase LWCULINE phase Percent Loss calculated for each of 3 transformer phases YLWCUphase 100x LWCUphase Veter X PTratio X METER X CTratio Sum the LWCUphase results and apportion 1 3 of the system losses LWCU y to each of the 3 meter elements Calculate TLC coefficient calculated for each of 3 meter elements Kweu LWCUavg meter X CTratio c FE VARS LOSS Kvre Transformer test VA losses calculated for each of 3 transformer phases NLVAphase YOEC x VAT 100 Transformer test VAR losses calculated for each of
23. y windings Form 5 3 wire delta Three transformer phases A B C measured with two internal meter elements A and C The meter elements measure the phase voltages and the line currents not phase currents Form 5 3 wire Y Three transformer phases A B C measured with two internal meter elements A and C The meter elements measure the phase currents and the line line voltage not phase voltages Form 5 open delta and network Two transformer phases A and C measured with two internal meter elements A and C The meter elements directly measure the transformer phase voltages and currents The JEMStar meter performs loss compensation at the individual element level JEMStar calculates and compensates the watts and VAR measurements for each meter element individually so each meter element has its own TLC coefficients The individual element compensated watt and VAR measurements are then summed to form the total system measurement In all cases except Form 8 the TLC coefficients for each of the meter elements are identical in value The general calculation steps are as follows 1 JEMWare calculates the transformer watts and VAR losses on a per transformer phase basis when the meter is running at its nominal voltage and test current 2 The program sums the transformer per phase losses resulting in the total system losses 3 The program apportions the total system losses among the meter elements and calculates TLC coefficients for
Download Pdf Manuals
Related Search