Series PM170 Powermeters

Transcription

1 Series PM0 Powermeters Installation and Operation Manual This manual is intended for the user of any one of the Series PM0 Powermeters. It provides installation and setup instructions for the instrument, including communications. For additional information on using communications, refer to the Series PM0 Communications Manual. All installation and setup procedures must be performed by qualified persons only. IMPORTANT For the safety of personnel and equipment, it is essential to read this manual prior to using the equipment.

2 LIMITED WARRANTY The manufacturer offers the customer an -month functional warranty on the instrument for faulty workmanship or parts from date of dispatch from the distributor. In all cases, this warranty is good for months from the date of production. This warranty is on a return to factory basis. The manufacturer does not accept liability for any damage caused by instrument malfunction. The manufacturer accepts no responsibility for the suitability of the instrument to the application for which it was purchased. Failure to install, set up or operate the instrument according to the instructions herein may void the warranty. Your instrument should only be opened by a duly authorized representative of the manufacturer. The unit should only be opened in a fully anti-static environment. Failure to do so may damage the electronics and will void the warranty. NOTE The greatest care has been taken to manufacture and calibrate your instrument. However, these instructions do not purport to cover all possible contingencies that may arise during installation, operation or maintenance, and all details and variations of this equipment do not purport to be covered by these instructions. For additional information regarding installation, operation or maintenance of this instrument, contact the manufacturer or your local representative or distributor. BG00 REV. J

3 Contents Initial Inspection Mechanical Installation Electrical Installation. Power Supply Connections. Voltage Inputs. Current Inputs. Wiring Configurations. Communications Connections - Optional. External Synchronization Input - Optional Turning on the Powermeter Initial Setup Viewing the Displays Appendix: Technical Specifications List of Figures Figure - Dimensions and Mounting Figure - Locations of Terminals & Communication Connector Figures Wiring Configurations - Figure - Communications Adapters Figures Communications Cable Connections: Computer 9-0 Figures Communications Cable Connections: Printer Figures Communications Cable Connections: Modem Figure - Display Example Figure - Panel Detail List of Tables Table - Terminals: D Type Adapter Table - Terminals: Terminal Block Adapter Table - Basic Setup Parameters Table - Communications Setup Parameters Table - Displayed Parameters - PM0 Table - Displayed Parameters - PM0E Table - Displayed Parameters - PM0M 8

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5 Initial Inspection Confirm that the instrument is damage-free, and only then test the electrical performance. Under no circumstances should the instrument be connected to a power source if it is damaged. Check that the instrument conforms to your order (appropriate power supply, voltage and current input options). Mechanical Installation Location away from heat sources in a dirt-free environment away from direct sunlight no contact with oil, moisture or rain away from very high electric fields Mounting Procedure Prepare the panel cut-out, x mm, prior to mounting. Lock the instrument into place using the supplied latches (see Figure -). STEP : Place the instrument through the cut-out. STEP : Assemble the latches onto the outer wall of the enclosure. STEP : Tighten the screws, torque 0 Oz Inch (0. N m). Figure - Dimensions and Mounting System

6 Electrical Installation Before performing any installation procedure, ensure that all incoming power sources are shut OFF. Failure to observe this practice can result in serious or even fatal injury and damage to equipment. PIN COMMUNICATION PORT 8 V V V V N VOLTAGE INPUTS CURRENT INPUTS A or A POWER SUPPLY 0V AC or 0V AC 9 I C I B I A N 0 L GROUND CONNECTIONS TERMINAL BLOCK SUPPRESSION CORE EL0009 WIDE N L 0VAC OR 0VAC PM0 Figure - Locations of Terminals and Communication Connector: Rear View

7 . Power Supply Connections Use the suppression core provided for connecting the live line to terminal and the neutral to terminal 0.. Voltage Inputs 0V Input (Standard) Use any of the five wiring configurations shown in Figures - through -. 0V Input (Option U) 0V input usually implies use of a potential transformer (PT). Use either of the wiring configurations shown in Figures - and -.. Current Inputs The secondary of a current transformer must never be allowed to be open circuit when the primary is energized. An open circuit can cause high voltages, possibly resulting in equipment damage, fire and even serious or fatal injury. Ensure that the current transformer wiring is made through shorting switches and is secured using an external strain relief to reduce mechanical strain on the screw terminals, if necessary. The CTs must be connected in the correct order and with the correct polarity as shown in the wiring diagrams for the instrument to operate properly. If the instrument displays a power factor of zero or close to it, or if power readings show unreasonable values, this may indicate that the polarity of the CT connections is reversed.. Wiring Configurations Wire Direct Wire Direct Wire Wye (with PT) Wire Direct Delta Wire Open Delta (with PT)

8 Figure - Wire Direct Connection Wiring Mode: dir Figure - Wire Direct Connection Wiring Mode: L-n or L-L

9 Figure - Wire Wye Connection via PT Wiring Mode: L-n or L-L Figure - Wire Direct Delta Connection Wiring Mode: L-n or L-L

10 .0 Figure - Wire Open Delta Connection via PT Wiring Mode: OP. Communication Connections - Optional Adapters EIA RS-, RS- and RS-8 communication lines are connected to the PM0 via the communication adapter, which must be installed on the -pin female connector on the rear of the instrument. The two types of communication adapters, D Type and Terminal Block, are shown in Figure -. NO LONGER AVAILABLE D Type Communication Adapter Terminal Block Communication Adapter Figure - Communication Adapters

11 Connecting the D Type Adapter. Plug the -pin male end of the adapter into the Powermeter connector (port) and tighten the screws.. Connect your serial line to the adapter s -pin female plug. Connecting the Terminal Block Adapter. Plug the -pin male end of the adapter into the Powermeter connector (port) and tighten the screws.. Connect your communications lines to the terminal block of the communication adapter. The terminals and their functions for the two adapter types are listed in Tables - and -. Table - Terminals: D Type Adapter Pin Terminal Function Signal OV Common (signal ground) RS- TXD Transmit Data RS- RXD Receive Data RS- Data Terminal Ready RS- DSR/CTS Data Set Ready/Clear To Send RS- TXD+ + Transmit Data RS-/RS-8 RXD+ + Receive Data RS-/RS-8 TXD- - Transmit Data RS-/RS-8 RXD- - Receive Data RS-/RS-8 Table - Terminals: Terminal Block Adapter Terminal Function RS- TXD Transmit Data RXD DSR RS-/RS-8 TX RX -TX -RX Receive Data Data Terminal Ready Data Set Ready/Clear To Send Common (signal ground) + Transmit Data NOTE: For RS-8 communications, connect + Receive Data together terminals TX and - Transmit Data RX, and terminals -TX and -RX. - Receive Data

12 Cable Connections RS- communication allows a single point-to-point connection (one instrument to the serial port of the computer, printer or modem. A flat cable can be used. Cable length may be maximum m. RS-/RS-8 communications allow connection of up to instruments to one host computer or PLC. The total cable length may be 00m, using gauge shielded, twisted pair cables. RS- (full duplex) requires wires; RS-8 (half duplex), wires. To minimize reflections and reduce cross talk, it is recommended to terminate line ends with termination resistors RT and RT of 0-00 Ohm, 0.W. The manufacturer s RS- to RS-/RS-8 converter has an internal termination resistor and does not require the RT external resistor. When lines are routed through an electrically noisy environment, input protection against switching or lightninginduced surge voltages is required in addition to line termination. Surge voltages can be generated by switching operations in power substations, or can occur as a result of voltage deep fade, phase gating controls, contactor relay controls, etc. Transient surge voltage effects may disable the master PC or PLC and in the worst case lead to destruction of unprotected electronic components. 8

13 Computer Connections RS- POWERMETER DSR/CTS -PIN DB FEMALE CONNECTOR GND DSR RTS CTS 0 IBM PC/ COMPATIBLE / Figure -8 RS- Simple -Wire Connection, -pin POWERMETER # # RS- DSR/CTS -PIN DB FEMALE CONNECTOR GND DSR RTS CTS 0 IBM PC/ COMPATIBLE Figure -0 RS- Hardware Handshaking Connection, -pin POWERMETERS RS-/RS-8 Tx Rx Shield Shield / OR RS-/RS- CONVERTER -PIN DB FEMALE CONNECTOR RT IBM PC/COMPATIBLE CTS- - - RTS CTS Rx- Tx- RTS- POWERMETER RS- DSR/CTS 9-PIN DB9 FEMALE CONNECTOR GND DSR RTS CTS 8 IBM PC/ COMPATIBLE / Figure -9 RS- Simple -Wire Connection, 9-pin RS- POWERMETER DSR/CTS 9-PIN DB9 FEMALE CONNECTOR GND DSR RTS CTS 8 IBM PC/ COMPATIBLE Figure - RS- Hardware Handshaking Connection, 9-pin # # POWERMETERS RS-/RS-8 Tx Rx Shield Shield IBM PC/COMPATIBLE RT CTS- - - RTS CTS Rx- Tx- RTS / 8 9 Tx Tx Rx Rx Tx- Tx- Rx- Rx- # Shield # Shield Tx Tx Rx Tx- Rx- RT Rx Tx- Rx- RT c0-000 PM0 c PM0 Figure - RS- Multidrop Connection, -pin Figure - RS- Multidrop Connection, 9-pin 9

14 POWERMETERS RS-/RS-8 IBM PC/COMPATIBLE OR RS-/RS- CONVERTER -PIN DB FEMALE CONNECTOR # Tx Rx Tx- Rx- Shield Shield RT - - RTS CTS RTS- CTS- # Tx Rx Tx- Rx- Shield # Tx Rx RT Tx- Rx- c0-000 PM0 Figure - RS-8 Multidrop, -pin POWERMETERS RS-/RS-8 IBM PC/COMPATIBLE A 9-PIN DB9 FEMALE CONNECTOR # # Tx Rx Tx- Rx- Shield Shield RT - - RTS CTS RTS- CTS- 8 9 Tx Rx Tx- Rx- Shield # Tx Rx RT Tx- Rx- c PM0 Figure - RS-8 Multidrop, 9-pin 0

15 Printer Connections RS- POWERMETER DSR/CTS -PIN DB FEMALE CONNECTOR GND DSR 0 CTS PRINTER / Figure - Simple -Wire Connection, -pin DTE Printer POWERMETER RS- DSR/CTS -PIN DB MALE CONNECTOR GND DSR RTS 0 PRINTER / Figure -8 Simple -Wire Connection, -pin DCE Printer RS- POWERMETER DSR/CTS 9-PIN DB9 FEMALE CONNECTOR GND DSR CTS 8 Figure - Simple -Wire Connection, 9-pin DTE Printer POWERMETER RS- GND DSR/CTS DSR RTS PRINTER / 9-PIN DB9 MALE CONNECTOR Figure -9 Simple -Wire Connection, 9-pin DCE Printer PRINTER /8 POWERMETER RS- -PIN DB FEMALE CONNECTOR DSR/CTS GND DSR 0 PRINTER CTS /9 RS- POWERMETER DSR/CTS 9-PIN DB9 FEMALE CONNECTOR GND PRINTER DSR CTS /0 Figure -0 Hardware Handshaking Connection, -pin DTE Printer Figure - Hardware Handshaking Connection, 9-pin DTE Printer RS- POWERMETER DSR/CTS -PIN DB MALE CONNECTOR GND PRINTER 0 DSR RTS / RS- POWERMETER DSR/CTS 9-PIN DB9 MALE CONNECTOR GND PRINTER DSR RTS / Figure - Hardware Handshaking Connection, -pin DCE Printer Figure - Hardware Handshaking Connection, 9-pin DCE Printer

16 Modem Connection RS- POWERMETER DSR/CTS -PIN DB MALE CONNECTOR GND MODEM / Figure - Connection for -pin Modem Connector POWERMETER. External Synchronization Input - Optional RS- DSR/CTS 9-PIN DB9 MALE CONNECTOR GND MODEM / Figure - Connection for 9-pin Modem Connector External synchronization can be used in the PM0E and PM0M for power demand interval measurements. External synchronization requires a timing pulse from the source utility company indicating the beginning of the demand interval. The signal is delivered via pins and on the Powermeter s communication connector (port). If you are using the optional communication adapter, the external synchronization source should be connected as follows: if D Type adapter: to pins and on the -pin female side of the adapter; if Terminal Block adapter: to terminals EXT. and EXT. on the terminal block of the adapter. A utility pulse signal should be supplied via a volt-free relay contact having a minimum rating of V DC, 0.A. The minimum pulse width is 0 ms. Turning on the Powermeter Connect the Powermeter to a suitable power supply. If a diagnostic code other than 8 constantly appears when you apply power to the instrument, contact your local distributor for instructions. Upon power up, the Powermeter assumes the working mode. In this mode, the Powermeter executes measurement functions and displays the results on the front panel (see Section, Viewing the Displays).

17 Initial Setup Correct definition of the setup parameters is essential to proper functioning of the instrument and correct readings. A typical setup menu display is shown in Figure -. PM0E Menu Window Procedure Figure - Display Example Option Window Upon power up, the instrument is in the working mode. Press the SELECT key to enter the configuration mode. The small arrow LEDs will cease to be lit up. Use the arrow keys to scroll up or down the pages until the code for the parameter you want to define appears in the upper window. The menu list is circular, i.e., when you reach the last parameter and continue to scroll down, the first parameter will appear. When you are selecting a setup parameter, the menu (upper) window is the active window. This is indicated by a dot following the menu code. When you are ready to choose an option/value for the selected parameter, you must make the option (lower) window the active window. For communications setup parameters, there may be two options together, which will be displayed in this case in the middle and lower windows.

18 Press the SELECT key and hold; while holding, press the up arrow key as well, and hold both for about seconds, until the dot in the menu window disappears. Now the option window is active. Use the up and down arrow keys to choose the desired option/value. When the desired option/value appears in the option window, press the ENTER key. The chosen option/value has now been entered, and the dot will reappear in the menu window, indicating that the menu window is now active. Press ENTER to exit the configuration mode and return to the working mode. Example: Wiring Mode Setup CnF. Press SELECT to enter the configuration mode. Use the arrow keys to scroll up or down until CnF. appears in the upper window. OP The lower window will have the current configuration of the wiring mode. Next, make the lower window the active CnF window, as follows: Press the SELECT key and hold; while holding, press the up arrow key as well, and OP hold both keys for about seconds, until the dot in the upper window disappears. Now the lower window is active, and you are ready to change the wiring mode. Use the up and down arrow keys to choose the desired option. When the desired option appears in the option CnF. window, press ENTER. (In this example we changed the wiring mode to L-n). The L-n chosen option has now been entered, and the dot will reappear in the upper window, indicating that the upper window is now active. Press ENTER to exit the configuration mode. Tables. and. list the basic and communications setup parameters and the available options/values for each.

19 Table - Basic Setup Parameters Menu Parameter Options / Description Code Name Value Range CnF. Wiring Mode OP -wire Open delta L-n dir L-L -wire Line-to-neutral mode -wire Direct connection -wire Line-to-line mode Pt. PT Ratio.0 to 00.0 The turns ratio of the potential transformers Ct. CT Primary Current P. Power Demand Period AP. Ampere Demand Period to 0000 The primary current rating of the phase current transformers, in A (amperes),,,0,,0, The length of the demand period for 0,0,E power demand calculations, in minutes E = external synchronization 0 to 800 The length of the demand period for ampere demand calculations, in seconds; 0 = measuring peak currents buf. Buffer Size nor,unst The number of measurements for RMS sliding averaging: nor - normal buffer (8 entries) UnSt - unstable conditions ( entries) rst. RESET Enable/Disable OFF, On Protects against inadvertent reset via the front panel. When set to OFF, this function is disabled Table - Communications Setup Parameters (These parameters appear only if the optional communications adapter is connected). Menu Parameter Options / Description Code Name Value Range br. Data Format and Baud Rate Data Formats: E, 8n, 8E Baud Rates: 0, 00, 00, /8 bit, even/no parity bps 00, 00, 800, or 900 Add. Address 0 to Communication address H.Sh. Handshaking SOFt Software handshaking (XON/XOFF protocol) CoP. (PM0E, PM0M) Communications Protocol and Interface HArd Protocol: ASCI, rtu or Prnt Interface:, or 8 Hardware handshaking (CTS protocol). signal permanently asserted high ASCII, Modbus or Print RS-, RS- or RS-8 Pr. Printout Period*,,, 0,, 0, 0, 0 Time interval between successive printouts, in minutes *for Print mode only; see the Series PM0 Communications Manual

20 Viewing the Displays To the right of each window on the panel, a small arrow LED will light up. This arrow indicates which parameter, or page, is being displayed. For real-time parameters, the arrow will be lit up continuously; for ampere or kw/kva demand measurements, the arrow will flash. Arrow LED Window Figure - Panel Detail The arrow lit up continuously is denoted in Tables -, - and - as. The flashing arrow is denoted as. Table - Displayed Parameters - PM0 Page Window Parameter Unit Range (upper) Voltage L/L V/kV 0 to kv (middle) Voltage L/L V/kV 0 to kv (lower) Voltage L/L V/kV 0 to kv (upper) Current L A/kA 0 to 0.00 ka (middle) Current L A/kA 0 to 0.00 ka (lower) Current L A/kA 0 to 0.00 ka (upper) Total kw kw/mw -999 to MW (middle) Total power factor to.00 (lower) Frequency Hz.0 to.0 Hz (upper) Max. ampere demand L A/kA 0 to 0.00 ka (middle) Max. ampere demand L A/kA 0 to 0.00 ka (lower) Max. ampere demand L A/kA 0 to 0.00 ka date (if RTC ordered) month.day year hour hour.minutes seconds

21 Table - Displayed Parameters - PM0E Page Window Parameter Unit Range Voltage L/L V/kV 0 to kv Voltage L/L V/kV 0 to kv Voltage L/L V/kV 0 to kv Current L A/kA 0 to 0.00 ka Current L A/kA 0 to 0.00 ka Current L A/kA 0 to 0.00 ka Total kw kw/mw -999 to MW Total power factor to.00 Frequency Hz.0 to.0 Hz kwh net kwh/mwh -999 to 9999 MWh kvar kvar/mvar -999 to Mvar kvarh net kvarh/mvarh -999 to 9999 Mvarh Max. ampere demand L A/kA 0 to 0.00 ka Max. ampere demand L A/kA 0 to 0.00 ka Max. ampere demand L A/kA 0 to 0.00 ka Max. kw demand kw/mw 0 to MW date (if RTC ordered) month.day year hour hour.minutes seconds

22 Table - Displayed Parameters - PM0M Page Window Parameter Unit Range Voltage L/L V/kV 0 to kv Voltage L/L V/kV 0 to kv Voltage L/L V/kV 0 to kv Current L A/kA 0 to 0.00 ka Current L A/kA 0 to 0.00 ka Current L A/kA 0 to 0.00 ka Total kw kw/mw -999 to MW Total kva kva/mva 0 to MVA Total power factor to.00 kwh net kwh/mwh -999 to 9999 MWh kvah kvah/mvah 0 to 9999 MVAh Frequency Hz.0 to.0 Hz Max. ampere demand L A/kA 0 to 0.00 ka Max. ampere demand L A/kA 0 to 0.00 ka Max. ampere demand L A/kA 0 to 0.00 ka Max. kw demand kw/mw 0 to MW Max. kva demand kva/mva 0 to MVA Power factor at maximum kva demand to.00 date (if RTC ordered) month.day year hour hour.minutes seconds 8

23 NOTES to Tables -, -, - When the value width exceeds the window resolution, the reading is converted to higher units and displayed with a decimal point. The right- most digits of the reading are truncated. The maximum range for energy readings is to 9, MWh/Mvarh/MVAh. Beyond this value, the reading rolls over to zero, and the corresponding display window flashes until the user presses any key. The Power Factor at kva maximum demand is calculated for the Demand Period when kva demand is the greatest. The Power Factor is calculated as follows: PF (Demand) = kw Demand/kVA Demand where kw Demand and kva Demand are the average powers (kw and kva) during the Demand Period. Additional Notes. L, L, and L line-to-neutral voltages correspond to A, B and C line-to-neutral voltages, and L, L, and L line-to-line voltages to AB, BC and CA line-to-line voltages.. Page displays are line-to-neutral voltages when the L-n WIRING MODE is selected. For all other wiring modes, only line-to-line voltages will be displayed.. The maximum acceptable value for CT PRIMARY CURRENT PT RATIO is 0,000,000. If this product is greater, power values will be zeroed. Resetting Accumulated Values To reset accumulated energies (PM0E/0M only): From the energies page (where arrows KWH and KVARH/KVAH are illuminated), press and hold the ENTER key for about seconds until displayed energies are reset to zero. To reset maximum demands (all Series 0 models): From the demand page (where arrows A, A and A, or KW/KVA flash), press and hold the ENTER key for about seconds until displayed maximum demands are reset to zero. The reset function can be disabled in the basic setup, to avoid unauthorized resetting of values. 9

24 Real Time Clock (RTC) - Optional The real time clock/calendar option provides information for real time control and data logging. The end of month date is automatically adjusted for months with less than days, including corrections for leap years. The clock operates in a -hour format. The real time clock function, unlike the basic setup parameters, is set up in the working mode (or through communications (see the Series PM0 Communications Manual). date. 8.0 In the working mode, use the arrow keys to scroll up or down the display pages parameter list until date. appears in the upper window. 0 The middle window will contain the day and month. In the example at the left, the clock is set to the rd of August. The lower window will contain the year in two-digit format; in our example, the year is 00. To change the date: Press the SELECT key repeatedly until the element of the date (day or month or year) that you wish to change blinks. Then use the up arrow to set that element of the date. When the date has been set, press the ENTER/RESET key and the window will cease blinking. To set the time, move to the following page using Hour. the arrow key, so that hour. appears in the upper 09. window..0 The middle window will contain the hour and minute; the lower window will contain the seconds (9::0 a.m. in the example at left). To change the time: Press the SELECT key repeatedly until the element of the time that you wish to change (hour or minute) blinks. Then use the up arrow to set that element of the time. When the time has been set, press the ENTER/RESET key and the window will cease blinking. As with any clock, you cannot set the seconds but can reset them to zero. This is done by exiting the RTC setup while the seconds window is blinking. 0

25 Appendix: Technical Specifications Input & Output Ratings Voltage inputs 0 V: standard 0 V: option DIRECT INPUT (up to 0V line-to-line voltage, or up to 0V where the wiring mode is set to OP). Burden: <0. VA INPUT USING PT (up to 0V+0% line-toline voltage) Burden: <0.0 VA INPUT USING PT (up to 0V+0% line-toline voltage). Burden: <0.0 VA Display Current inputs Input terminals A: standard A: option External synchronization input (optional, PM0E/0M) Communications (optional) INPUT VIA CT with A secondary output, not to exceed A RMS; Burden: <0. VA Overload withstand: 0A RMS continuous, 0A RMS for second INPUT VIA CT with A secondary output, not to exceed.a RMS; Burden: <0. VA Overload withstand: A RMS continuous, 0A RMS for second Standard, UL recognized E008 Screw: M, brass, nickel plated Spring lock washer: M, brass, nickel plated Maximum wire diameter:. mm ( AWG) Dry contact, V DC/0.A EIA RS-, RS-, and RS-8 standards Connector: -pin female D-type or Terminal Block Display Power Supply Power supply (factory set) windows with high-brightness seven-segment digital LEDs 88-8V AC/-V AC, 0/0 Hz, 0VA

26 Measurement Specifications Accuracy, % Range Display resolution (%Rdg) Parameter Full scale Rdg FS range Voltage 0V PT@ 0V,L-N/OP 08V PT@ 0V,L-L/DIR 80V PT@ 0V,L-N/OP 0V PT@ 0V,L-L/DIR % to 0% FS Line current CT PRIMARY CURRENT % to 0% FS Active power 0. PT 0V input. PT 0V input Reactive power (PM0E/M) Apparent power (PM0M) 0. PT 0V input. PT 0V input 0. PT 0V input. PT 0V input 0. PF ,000 to +,,000 kw 0. PF ,000 to +,,000 kvar 0. PF 0. 0 to +,,000 kva Power factor PF to to 999,000 V V to 9,999 V 0,000 V to 999,000 V 0 to 0,000 A A to 9,999 A 0,000 A to 0,000 A kw to 9,999/-999 kw 0 MW to, MW - MW to -999 MW kvar to 9,999/-999 kvar 0 Mvar to, Mvar - Mvar to -999 Mvar kva to 9,999 kva 0 MVA to, MVA Frequency 0..0 to.0 Hz 0. Hz Unbalanced (neutral) CT PRIMARY CURRENT % to 0% 0 to 0,000 A A to 9,999 A current FS 0,000 A to 0,000 A Ampere demand same as for current kw demand (PM0E/M) same as for kw kva demand (PM0M) same as for kva

27 Accuracy, % Range Display resolution (%Rdg) Parameter Full scale Rdg FS range Active energy net (PM0E/M) Reactive energy net (PM0E/M) Apparent energy (PM0M). (typical). (typical). (typical) -999,999 to +9,999,999 kwh -999,999 to +9,999,999 kvarh 0 to +9,999,999 kvah PT = external potential transformer ratio CT, CT PRIMARY CURRENT = primary current rating of the external current 0% to 0% of voltage full scale and % to 0% of current full scale Higher resolution can be obtained via communications ± to 9,999/-999 kwh 0 MWh to, MWh - MWh to -999 MWh ± to 9,999/-999 kvarh 0 Mvarh to, Mvarh - Mvarh to -999 Mvarh ± to 9,999 kvah 0 MVAh to, MVAh When using external synchronization with a demand interval greater than 0 min., the measured power should not exceed,/(d x 0.) [MW/MVA], where D = demand interval in minutes Additional Notes. Accuracy is expressed as ± (percentage of reading + percentage of full scale) ± digit. This does not include inaccuracies introduced by the user's potential and current transformers.. Indicated accuracy specifications show the maximum allowed error. In fact, ordinary measurement error may be considerably less than the specified accuracy.. Specifications for kvar, kva and PF assume voltage and current waveforms with THD %.. Specifications assume a reference temperature of 0 - C.