63230-507-201A1 Instruction Bulletin Power Meter 750 Reference Manual Retain for future use.
HAZARD CATEGORIES AND SPECIAL SYMBOLS Read these instructions carefully and look at the equipment to become familiar with the device before trying to install, operate, service or maintain it. The following special messages may appear throughout this bulletin or on the equipment to warn of potential hazards or to call attention to information that clarifies or simplifies a procedure.
63230-507-201A1 03/2007 Power Meter 750 Table of Contents SECTION 1: INTRODUCTION Power Meter Hardware ............................................................................... 1 Power Meter Parts and Accessories ....................................................... 2 Box Contents ........................................................................................... 2 Firmware .....................................................................................................
Power Meter 750 Table of Contents 63230-507-201A1 03/2007 APPENDIX A: SPECIFICATIONS Power Meter Specifications ...................................................................... 31 APPENDIX B: REGISTER LIST Register List ............................................................................................. 33 Supported MODBUS Commands ............................................................. 48 How Signed Power Factor is Stored in the Register ................................
63230-507-201A1 03/2007 Power Meter 750 Section 1—Introduction SECTION 1— INTRODUCTION POWER METER HARDWARE Figure 1–1 below shows the parts of the Power Meter 750. Table 1–1 describes the parts. Figure 1–1: Parts of the Power Meter 750 1 2 B A A B Table 1–1: 4 3 Parts of the Power Meter Number © 2007 Schneider Electric All Rights Reserved 5 6 7 Part Description 1 Control power supply connector Connection for control power to the power meter.
Document Title English Section 1—Introduction 63230-507-201A1 03/2007 Power Meter Parts and Accessories Table 1–2: Power Meter Parts and Accessories Description Power Meter with Integrated Display Box Contents FIRMWARE 2 • • • • Model Number PM750 PM750MG One (1) power meter Two (2) retainer clips One (1) installation sheet One (1) RS485 Terminator (MCT2W) This instruction bulletin is written to be used with firmware version 3.000 and later.
63230-507-201A1 03/2007 Power Meter 750 Section 2—Safety Precautions SECTION 2— SAFETY PRECAUTIONS BEFORE YOU BEGIN This section contains important safety precautions that must be followed before attempting to install, service, or maintain electrical equipment. Carefully read and follow the safety precautions outlined below. DANGER HAZARD OF ELECTRIC SHOCK, EXPLOSION, OR ARC FLASH • Apply appropriate personal protective equipment (PPE) and follow safe electrical work practices. In the USA, see NFPA 70E.
Document Title English Section 2—Safety Precautions 4 63230-507-201A1 03/2007 © 2007 Schneider Electric All Rights Reserved
63230-507-201A1 03/2007 Power Meter 750 Section 3—Operation SECTION 3— OPERATION OPERATING THE DISPLAY The power meter is equipped with a large, back-lit LCD display. It can display up to five lines of information plus a sixth row of menu options. Figure 3– 1 shows the different parts of the power meter display. Figure 3– 1: Power Meter Display A B C A. Type of measurement B. Alarm indicator ) C. Maintenance icon D. Bar Chart (%) E. Units K F. Menu items G. Selected menu indicator H.
Power Meter 750 Section 3—Operation 63230-507-201A1 03/2007 to “Press PHASE,” you would press and release the button below the PHASE menu item. • Changing Values MENU OVERVIEW Changes are automatically saved and take effect immediately. When a value is selected, it flashes to indicate that it can be modified. A value is changed by doing the following: • • Press + or <- to change numbers or scroll through available options. • To save your changes and move to the next field, press OK.
63230-507-201A1 03/2007 Power Meter 750 Section 3—Operation SETTING UP THE POWER METER The power meter ships with many default values already set up in the meter. These values may be changed by navigating to the appropriate screen and entering new values. Other values may be changed using the Reset function. Use the instructions in the following sections to change values. See “Reset the Power Meter” on page 12 for more information on the Reset function.
Power Meter 750 Section 3—Operation 63230-507-201A1 03/2007 Set Up CTs 1. In SETUP mode, press ###: until METER is visible. #4 2!4)/ 2. Press METER. 3. Press CT. 4. Enter the PRIM (primary CT) number. 5. Press OK. # 4 6. Enter the SEC. (secondary CT) number. 7. Press OK to return to the METER SETUP screen. 8. Press 1; to return to the SETUP screen. # 4 02)3%# /+ Set Up PTs 1. In SETUP mode, press ###: until METER is visible. 2. Press METER. PT RATIO 1 120 120 3. Press PT. 4.
63230-507-201A1 03/2007 Power Meter 750 Section 3—Operation Set Up Demand Current and Power 1. In SETUP mode, press ###: until DMD (demand) is visible. 2. Press DMD (demand setup). 3. Enter the MIN (demand interval in minutes) for I (current): 1 to 60. 4. Press OK. $%-!.$ 3%450 5. Enter the MIN (demand interval in minutes) for P (power): 1 to 60. 0 6. Press OK. 0 7. Enter the SUB-I (number of subintervals) for P: 1 to 60. ) -3%# -). -). -3%# 35" ) +6!2( /+ 8.
Power Meter 750 Section 3—Operation 63230-507-201A1 03/2007 Set Up Communications 1. In SETUP mode, press ###: until COM is visible. 2. Press COM. #/- 3%450 3. Enter the ADDR (meter address): 1 to 247. %UDM 4. Press OK. 5. Select the BAUD (baud rate): 2400, 4800, 9600, or 19200. 6. Press OK. !$$2 A@T$ 0@Q LATR 7. Select the parity: EVEN, ODD, or NONE. 8. Press OK to return to the SETUP MODE screen. /+ NOTE: Default values are displayed. Set Up the Bar Graph Scale 1.
63230-507-201A1 03/2007 Power Meter 750 Section 3—Operation Set Up Meter Mode NOTE: The meter Mode is set up using the RESET menu. Follow the “Power Meter Setup” instructions on page 7 but select RESET instead instead of SETUP. The meter mode is only a visualization mode. It does not change or affect the way the PM750 performs its calculations. 1. In RESET mode, press ###: until MODE is visible. 2. Press MODE. RDKDBS LN$D 3.
Power Meter 750 Section 3—Operation 63230-507-201A1 03/2007 VIEW THE METER INFORMATION 1. Press ###: until MAINT(maintenance) is visible. 2. Press MAINT. -%4%2 ).&/ 3. Press INFO (meter info). 4. View the meter information (model number, operating system firmware version, reset system firmware version, and power meter serial number). 0 - 5. Press 1; to return to the MAINTENANCE screen. ).&/ 2%3%4 -/$%, 2 3 3 .
63230-507-201A1 03/2007 Power Meter 750 Section 3—Operation Resetting Individual Values Individual values for Energy, Demand, Min/Max, Mode, and Timer can be reset without affecting other values. Below are instructions for resetting Energy values. Resetting Energy Values 1. From the MAINTENANCE screen, press RESET. 2. Enter the RESET password (00000 is the default). 2%3%4 %.%2'9 3. Press OK. 4. Press E. 5. Press NO or YES. 6. Press 1; to return to the MAINTENANCE screen. .
Power Meter 750 Section 3—Operation 14 63230-507-201A1 03/2007 © 2007 Schneider Electric All Rights Reserved
63230-507-201A1 03/2007 Power Meter 750 Section 4—Metering SECTION 4— METERING POWER METER CHARACTERISTICS METERING CAPABILITIES The power meter measures currents and voltages and reports in real time the rms values for all three phases and neutral. In addition, the power meter calculates power factor, real power, reactive power, and more. Table 4– 1 lists metering characteristics of the PM750.
Power Meter 750 Section 4—Metering 63230-507-201A1 03/2007 Table 4– 1: Power Meter Characteristics (continued) Local or Remote Setup Type of distribution system Rating of current transformers Voltage 3-phase 3- or 4-wire with 1, 2, or 3 CTs, two- or single-phase Primary 5 to 32,767 A Secondary 5 or 1 A Primary 3,276,700 V max Secondary 100, 110, 115, 120 Calculation interval for demand currents 1 to 60 minutes Calculation interval for demand power 1 to 60 minutes MODBUS RS485 Functions RS485 link 2
63230-507-201A1 03/2007 Power Meter 750 Section 4—Metering Table 4– 2: Demand Readings (continued) Demand Reactive Power, 3Ø Total Last Complete Interval 0 to 3276.70 MVAR Peak 0 to 3276.70 MVAR Demand Apparent Power, 3Ø Total Demand Power Calculation Methods Last Complete Interval 0 to 3276.70 MVA Peak 0 to 3276.70 MVA Demand power is the energy accumulated during a specified period divided by the length of that period.
Power Meter 750 Section 4—Metering 63230-507-201A1 03/2007 Figure 4– 1: Block Interval Demand Examples Demand value is the average for the last completed interval 15-minute interval Time (sec) Sliding Block Demand value is the average for last completed interval Calculation updates at the end of the interval 15-minute interval 15 15-min 15-minute interval 30 45 Time (min) Fixed Block Demand value is the average for last completed interval Calculation updates at the end of the subinterval (5
63230-507-201A1 03/2007 Power Meter 750 Section 4—Metering Figure 4– 2: Thermal Demand Example The interval is a window of time that moves across the timeline. 99% 90% % of Load Last completed demand interval 0% Time (minutes) 15-minute interval next 15-minute interval Calculation updates at the end of each interval Demand Current The power meter calculates demand current using the thermal demand method.
Power Meter 750 Section 4—Metering 20 63230-507-201A1 03/2007 © 2007 Schneider Electric All Rights Reserved
63230-507-201 03/2007 Power Meter 750 Section 5—Input/Output Capabilities SECTION 5— INPUT/OUTPUT CAPABILITIES DIGITAL INPUTS The power meter can accept two digital inputs designated as S1 and S2. A digital input is used to detect digital signals. For example, the digital input can be used to determine circuit breaker status, count pulses, or count motor starts.
Power Meter 750 Section 5—Input/Output Capabilities 63230-507-201 03/2007 Figure 5– 2:Demand synch pulse timing Normal Demand Mode External Synch Pulse Demand Timing Billing Meter Demand Timing Billing Meter Demand Timing PLSD110140 Utility Meter Synch Pulse Setting Up the Digital Inputs Power Meter Demand Timing Power Meter Demand Timing (Slaved to Master) Use this procedure to set up the digital inputs. 1. In SETUP mode, press ###: until D IN (digital inputs) is visible. 2. Press D IN.
63230-507-201 03/2007 DIGITAL OUTPUT Solid-state KY Pulse Output Power Meter 750 Section 5—Input/Output Capabilities The PM750 has one digital output.The digital output has three operating modes: • External—This is the default setting. The output can be controlled by a command sent over the communications link. To de-energize the digital output, write the value 3320 to register 4126. To energize the digital output, write 3321 to register 4126.
Power Meter 750 Section 5—Input/Output Capabilities Calculating the Kilowatt-hour- Per-Pulse Value 63230-507-201 03/2007 This section shows an example of how to calculate kilowatt-hours per pulse. To calculate this value, first determine the highest kW value you can expect and the required pulse rate. In this example, the following assumptions are made: • • The metered load should not exceed 1600 kW. About two KY pulses per second should occur at full scale.
63230-507-201 03/2007 Power Meter 750 Section 5—Input/Output Capabilities Setting Up the Digital Output 1. In SETUP mode, press ###: until D OUT is visible. 2. Press D OUT. $/ 3%450 3. Select OFF or ON for the desired output mode by pressing +. Depending on which mode is set to ON, the other values change automatically. /M 4. Select ON for EXT to choose external mode. For setting up pulse or alarm output mode, see below. 5.
Power Meter 750 Section 5—Input/Output Capabilities 26 63230-507-201 03/2007 © 2007 Schneider Electric All Rights Reserved
63230-507-201A1 03/2007 Power Meter 750 Section 6—Alarms SECTION 6— ALARMS ABOUT ALARMS ALARMS The PM750 can detect 15 pre-configured alarms. A complete list of alarm configurations is described in Table 6– 1. All alarms can be configured with the following values when using the display except that digital alarms have a fixed pickup and dropout magnitude: • • • • • Enable—disable (default) or enable.
Power Meter 750 Section 6—Alarms 63230-507-201A1 03/2007 Table 6– 1: List of Default Alarms by Alarm Number (continued) Alarm Number Alarm Description Abbreviated Display Name Test Register Digital 14 Digital Input OFF/ON DIGITAL INPUT S1 4115 15 Digital Input OFF/ON DIGITAL INPUT S2 4116 ALARM SETUP When making alarm setup changes using the display, evaluation of all alarms is temporarily suspended while alarm setup screens are displayed.
63230-507-201A1 03/2007 Power Meter 750 Section 7—Maintenance and Troubleshooting SECTION 7— MAINTENANCE AND TROUBLESHOOTING CHAPTER 7 — MAINTENANCE AND TROUBLESHOOTING INTRODUCTION The power meter does not contain any user-serviceable parts. If the power meter requires service, contact your local sales representative. Do not open the power meter. Opening the power meter voids the warranty.
Power Meter 750 Section 7—Maintenance and Troubleshooting 63230-507-201A1 03/2007 Table 7– 1: Troubleshooting (continued) Incorrect setup values. The data being Incorrect voltage inputs. displayed is inaccurate or not what you expect. Power meter is wired improperly. See Appendix C—Instrument Transformer Wiring: Troubleshooting Guide on page 51 for more information on troubleshooting wiring problems. Power meter address is incorrect.
63230-507-201A1 03/2007 Power Meter 750 Appendix A—Specifications APPENDIX A—SPECIFICATIONS POWER METER SPECIFICATIONS Table A– 1: Specifications Electrical Characteristics True rms up to the 15th harmonic on three-phase AC system (3P, 3P + N) Type of measurement 32 samples per cycle Measurement Accuracy Current 0.4% from 1A to 6A Voltage 0.3% from 50 V to 277 V Power Factor 0.5% from 1A to 6A Power 0.5% Frequency ±0.02% from 45 to 65 Hz Real Energy IEC 62053-22 Class 0.
Power Meter 750 Appendix A—Specifications 63230-507-201A1 03/2007 Table A– 1: Specifications (continued) Metering category (voltage inputs and control power) CAT III, for distribution systems up to 277 V L-N / 480 V AC L-L Dielectric withstand As per IEC61010, UL508 Double insulated front panel display Altitude 3000 m Electromagnetic Compatibility Electrostatic discharge Level III (IEC 61000-4-2) Immunity to radiated fields Level III (IEC 61000-4-3) Immunity to fast transients Level III (IEC 61
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List APPENDIX B—REGISTER LIST CHAPTER 2 — MAINTENANCE AND TROUBLESHOOTING REGISTER LIST ALARMS Table B– 1: Register Listing—Setup and Status Setup & Status Reg Name Size Type Access NV Scale Units Range Notes 1090 Reserved 2 Float RO N - - - Reserved 1120 Reserved 2 Float RO Y - Amp - Current, N, Minimum 1140 Reserved 2 Float RO Y - % - Current, N, THD Minimum 1170 Reserved 2 Float RO Y - Amp - C
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 Table B– 1: Register Listing—Setup and Status (continued) Setup & Status Reg Name Size Type Access NV Scale Units Range Notes bit0: VA Clipping bit1: VB Clipping bit2: VC Clipping bit3: IA Clipping bit4: IB Clipping bit5: IC Clipping bit6: Freq Invalid 4112 Error Bitmap 1 Integer RO N - - - 4117 Thermal Demand Interval 1 Integer R/W Y - Minutes 1-60 Current Demand Only 4118 Power Block Demand Interval 1 Intege
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List The PM750 includes registers in two different formats: integer and floating point. For example, Real Power A is included in Register 1066 and 1067 (floating point) and register 4036 (integer).
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 Table B– 2: Register Listing—Metered Data (continued) Metered Data Reg Name Size Type Access NV Scale Units Range 1070 Notes Real Power, C 2 Float RO N - kW - 1072 Apparent Power, A 2 Float RO N - kVA - 1074 Apparent Power, B 2 Float RO N - kVA - 1076 Apparent Power, C 2 Float RO N - kVA - 1078 Reactive Power, A 2 Float RO N - kVAR - Signed Net Power 1080 Reactive Power, B 2 Float R
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List Table B– 2: Register Listing—Metered Data (continued) Metered Data Reg Name Size Type Access NV Scale Units Range Notes 4011 Voltage, L-N, 3P Average 1 Integer RO N V Volt/Scale 0-32767 4012 Current, 3P Average 1 Integer RO N I Amp/Scale 0-32767 4013 Frequency 1 Integer RO N 0.
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 Table B– 2: Register Listing—Metered Data (continued) Metered Data Reg Name Size Type Access NV Scale Units Range 4047 Current, C, THD 1 Integer RO N 0.1 % 0-10000 4048 Power Factor, Total Signed 1 Integer RO N 0.0001 - 0-1 4049 Voltage, A-N, THD 1 Integer RO N 0.1 % 0-10000 4050 Voltage, B-N, THD 1 Integer RO N 0.1 % 0-10000 4051 Voltage, C-N, THD 1 Integer RO N 0.
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List Table B– 3: Register Listing—Demand Values (continued) Demand Values Reg Name Size Type Access NV Scale Units Range 1048 Current, A, Demand Peak 2 Float RO Y - Amp - 1050 Current, B, Demand Peak 2 Float RO Y - Amp - 1052 Current, C, Demand Peak 2 Float RO Y - Amp - 4014 Real Power, Total Demand Present 1 Integer RO N W kW/Scale 0-32767 4015 Apparent Power, Total Demand Present 1 Integer RO N
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 Table B– 4: Register Listing—Min Max Values (continued) Min Max values Reg Name Size Type Access NV Scale Units Range 1108 Reactive Power, Total Minimum 2 Float RO Y - kVAR - 1110 Power Factor, Total Minimum 2 Float RO Y - - 0.0-1.0 1112 Frequency Minimum 2 Float RO Y - Hz 45.0-65.
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List Table B– 4: Register Listing—Min Max Values (continued) Min Max values Reg Name Size Type Access NV Scale Units Range 1160 Power Factor, Total Maximum 2 Float RO Y - - 0.0-1.0 1162 Frequency Maximum 2 Float RO Y - Hz 45.0-65.
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 Table B– 4: Register Listing—Min Max Values (continued) Min Max values Reg Name Size Type Access NV Scale Units Range 4059 Frequency Minimum 1 Integer RO Y 0.
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List Table B– 4: Register Listing—Min Max Values (continued) Min Max values Reg Name Size Type Access NV Scale Units Range 4085 Current, A, Maximum 1 Integer RO Y I Amp 0-32767 4086 Current, B, Maximum 1 Integer RO Y I Amp 0-32767 4087 Current, C, Maximum 1 Integer RO Y I Amp 0-32767 4089 Voltage, A-N, Maximum 1 Integer RO Y V Volt 0-32767 4090 Voltage, B-N, Maximum 1 Integer RO Y V Volt 0-3276
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 Table B– 5: Register Listing—I/O Setup and Status I/O Setup & Status Reg Name Size Type Access NV Scale Units Range Notes 4114 Digital Output Status 1 Integer RO N - - 0-1 0 = Off 1 = On 4115 Digital Input S1 Status 1 Integer RO N - - 0-1 0 = Off 1 = On 4116 Digital Input S2 Status 1 Integer RO N - - 0-1 0 = Off 1 = On 4129 Digital Output Mode 1 Integer R/W Y - - 0-2 0 = External Control (defa
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List Table B– 6: Register Listing—Alarm Setup and Status Alarm Setup & Status Reg Name Size Type Access NV Scale Units Range Notes 0 = Alarm OFF 1 = Alarm ON Bit 00 = Alarm Position 1 (Default Over kW-Total) Bit 01 = Alarm Position 2 (Default Over kVA-Total) Bit 02 = Alarm Position 3 (Default Over kVAR-Total) Bit 03 = Alarm Position 4 (Default Under PF-Total) Bit 04 = Alarm Position 5 (Default Over U 3-Phase) Bit 05 = Alarm Position 6 ((
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 Table B– 6: Register Listing—Alarm Setup and Status (continued) Alarm Setup & Status Reg Name Size Type Access NV Scale Units Range Notes 4156 Alarm Position 2 Configuration 16 - R/CW Y - - - See Alarm Configuration Template 4172 Alarm Position 3 Configuration 16 - R/CW Y - - - See Alarm Configuration Template 4188 Alarm Position 4 Configuration 16 - R/CW Y - - - See Alarm Configuration Template 4204
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List Table B– 6: Register Listing—Alarm Setup and Status (continued) Alarm Setup & Status Reg Name Size Type Access NV Scale Units Range Base + 6 Pickup Time Delay 1 Integer R/CW Y - Seconds 0 - 32767 Base + 7 Dropout Time Delay 1 Integer R/CW Y - Seconds 0 - 32767 Base + 8 Label 8 ASCII R/CW Y - - Notes RO = Read Only R/W = Read/Write NV = Nonvolatile.
Power Meter 750 Appendix B—Register List 63230-507-201A1 03/2007 SUPPORTED MODBUS COMMANDS Table B– 8: Command Description 0x03 Read holding registers 0x04 Read input registers 0x06 Preset single registers 0x10 Preset multiple registers Report ID Return String byte 1: 0x11 byte 2: number of bytes following without crc 0x11 byte 3: ID byte = 250 byte 4: status = 0xFF bytes 5+: ID string = PM710 Power Meter last 2 bytes: CRC Read device identification, BASIC implementation (0x00, 0x01, 0x02 data)
63230-507-201A1 03/2007 Power Meter 750 Appendix B—Register List When the power factor is lagging, the power meter returns a high negative value—for example, -31,794. This happens because bit 15=1 (for example, the binary equivalent of -31,794 is 1000001111001110). To get a value in the range 0 to 1,000, you need to mask bit 15. You do this by adding 32,768 to the value. An example will help clarify. Assume that you read a power factor value of -31,794. Convert this to a power factor in the range 0 to 1.
Power Meter 750 Appendix B—Register List 50 63230-507-201A1 03/2007 © 2007 Schneider Electric All Rights Reserved
63230-507-201A1 03/2007 Power Meter 750 Appendix C—Instrument Transformer Wiring: Troubleshooting Guide APPENDIX C—INSTRUMENT TRANSFORMER WIRING: TROUBLESHOOTING GUIDE Abnormal readings in an installed meter can sometimes signify improper wiring. This appendix is provided as an aid in troubleshooting potential wiring problems. SECTION I: USING THIS GUIDE The following sections contain “Case” tables showing a variety of symptoms and probable causes.
Power Meter 750 Appendix C—Instrument Transformer Wiring: Troubleshooting Guide 63230-507-201A1 03/2007 A quick check for proper readings consists of kW comparisons (calculated using the equation above and compared to the meter reading) and a reasonable lagging 3-phase average power factor reading. If these checks are okay, there is little reason to continue to check for wiring problems.
63230-507-201A1 03/2007 Power Meter 750 Appendix C—Instrument Transformer Wiring: Troubleshooting Guide Table C– 5: Section III—Case B Symptoms: 3-Wire Possible Causes 3 higher than A and C (except in • Phase B current is System Type 31) • kVA = about half of the expected magnitude • kW and kVAR can be positive or negative, less than about half of the expected magnitude • PF can be any value, probably a low leading value • One CT polarity is backwards Table C– 6: Section III—Case C Symptoms:
Power Meter 750 Appendix C—Instrument Transformer Wiring: Troubleshooting Guide 63230-507-201A1 03/2007 SECTION IV: 4-WIRE SYSTEM TROUBLESHOOTING Table C– 9: Section IV—Case A Symptoms: 4-Wire Possible Causes • kW = 1/3 of the expected value • kVAR = 1/3 of the expected value • power factor = 1/3 of the expected value • All else is normal • One CT polarity is backwards NOTE: The only way this problem will usually be detected is by the Quick Check procedure.
63230-507-201A1 03/2007 Power Meter 750 Appendix C—Instrument Transformer Wiring: Troubleshooting Guide Table C– 13: Section IV—Case E Symptoms: 4-Wire • kW = near 0 • kVA = near 0 • 3-phase average power factor flip-flopping lead and lag • Voltages, currents, and kVA are normal Possible Causes • Two CT secondary leads are swapped (A-phase on B-phase terminal, for example) • Two PT secondary leads are swapped (A-phase on B-phase terminal, for example) NOTE: In either case, the phase input that
Power Meter 750 Appendix C—Instrument Transformer Wiring: Troubleshooting Guide FIELD EXAMPLE 63230-507-201A1 03/2007 Readings from a 4-wire system • • • • • • • • • • • • • • kW = 25 kVAR = – 15 kVA = 27 I A = 904A I B = 910A I C = 931A I 3ΦAvg = 908A V AB = 495V V BC = 491V V CA = 491V V AN = 287V V BN = 287V V CN = 284V PF 3ΦAvg = 0.75 lag to 0.
63230-507-201A1 03/2007 Power Meter 750 Glossary GLOSSARY TERMS accumulated energy—energy can accumulates in either signed or unsigned (absolute) mode. In signed mode, the direction of power flow is considered and the accumulated energy magnitude may increase and decrease. In absolute mode, energy accumulates as a positive regardless of the power flow direction. active alarm—an alarm that has been set up to trigger the execution of a task or notification when certain conditions are met.
Power Meter 750 Glossary 63230-507-201A1 03/2007 minimum value—lowest value recorded of the instantaneous quantity such as Phase A Current, Phase A Voltage, etc., since the last reset of the minimums and maximums. nominal—typical or average. parity—refers to binary numbers sent over the communications link. An extra bit is added so that the number of ones in the binary number is either even or odd, depending on your configuration). Used to detect errors in the transmission of data.
230-507-201A1 03/2007 ABBREVIATIONS Power Meter 750 Glossary A—Ampere ADDR—Power meter address AMPS—Amperes BARGR—Bargraph COMMS—Communications CPT—Control Power Transformer CT—see current transformer on page 57 D IN—Digital Input D OUT—Digital Output DMD—Demand DO—Drop Out Limit ENABL—Enabled F—Frequency HZ—Hertz I—Current I/O—Input/Output IMAX—Current maximum demand kVA—Kilovolt-Ampere kVAD—Kilovolt-Ampere demand kVAR—Kilovolt-Ampere reactive kVARD—Kilovolt-Ampere reactive demand kVARH—Kilovolt-Amper
Power Meter 750 Glossary 63230-507-201A1 03/2007 PM—Power meter PQS—Real, reactive, apparent power PQSd—Real, reactive, apparent power demand PR—Alarm Priority PRIM—Primary PT—Number of voltage connections (see potential transformer on page 58) PU—Pick Up Limit PULSE—Pulse output mode PWR—Power Q—Reactive power Qd—Reactive power demand Qh—Reactive energy R.S.—Firmware reset system version S—Apparent power S.N.
63230-507-201A1 03/2007 A alarms abbreviated names defined 27 active 27 alarm conditions 27 setup 28 B block interval demand method 17 C calculating watthours per pulse 24 communications functions 16 setup 10 CT setup 8, 11 D default password 7 demand current 19 thermal 18 demand current calculation 19 demand power calculation 17 demand readings 16 demand current 19 demand power calculation methods 17 demand synch pulse method 21 diagnostics password 9, 28 digital inputs 16, 21 digital output 23 display
Power Meter 750 Index 63230-507-201A1 03/2007 English 62 © 2007 Schneider Electric All Rights Reserved
Schneider Electric 295 Tech Park Drive, Suite 100 Lavergne, TN 37086 Tel: +1 (615) 287-3400 www.schneider-electric.com Electrical equipment should be installed, operated, serviced, and maintained only by qualified personnel. No responsibility is assumed by Schneider Electric for any consequences arising out of the use of this material.
