AC Power Meter
GPM-8212

USER MANUALGW INSTEK PART NO. 82PM-82120MB

This manual contains proprietary information, which is protectedby copyrights. All rights are reserved. No part of this manual may
be photocopied, reproduced or translated to another language
without prior written consent of Good Will company.
The information in this manual was correct at the time of printing.
However, Good Will continues to improve products and reserves
the rights to change specification, equipment, and maintenanceprocedures at any time without notice.

Good Will Instrument Co., Ltd.
No. 7-1, Jhongsing Rd., Tucheng City, Taipei County 236, Taiwan.
ISO-9001 CERTIFIED MANUFACTURER

POWER METER.

USER MANUALTABLE OF CONTENTS
PAGE
1. SAFETY SUMMARY……………………………………………..

1

2. INTRODUCTION…………………………………………………

5

3. SPECIFICATION…………………………………………………

6

4. PANEL INTRODUCTION & WIRING…………………………

8

5. USAGE DESCRIPTION…………………………………………. 16
6. RS232 COMMUNICATION INTERFACE……………………... 18
7. MAINTENANCE…………………………………………………. 212POWER METER

POWER METERUSER MANUALUSER MANUAL1.SAFETY TERMS AND SYMBOLSDANGER High Voltage

Please take a moment to review these safety terms and symbols which
may appear in this manual or on Equipment to prevent damage to thePower Meter.
ATTENTION refer to Manual

WARNING. Warning statements identify condition orpractices that could result in injury or loss of life.

Protective Conductor Terminal

CAUTION. Caution statements identify conditions orpractices that could result in damage to this product or(ground) Earth Terminal

other property.

Frame or Chassis Terminal

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POWER METERUSER MANUALFOR UNITED KINGDOM ONLY

USER MANUALBlack.
The wire which is coloured Brown must be connected to theterminal marked with the letter L or P or coloured Brown or Red.

NOTE: This lead/appliance must only be wired by competentpersons
WARNING: THIS APPLIANCE MUST BE EARTHEDIMPORTANT: The wires in this lead are coloured inaccordance with the following code:
Green/ Yellow: EarthBlue:
NeutralBrown:
Live(Phase)

If in doubt, consult the instructions provided with the equipment
or contact the supplier.
This cable/appliance should be protected by a suitably rated andapproved HBC mains fuse : refer to the rating information on theequipment and/or user instructions for details. As a guide, cableof 0.75mm² should be protected by a 3A or 5A fuse. Larger
conductors would normally require 13A types, depending on theconnection method used.
Any moulded mains connector that requires removal/replacement must be destroyed by removal of any fuse & fusecarrier and disposed of immediately, as a plug with bared wires ishazardous if a engaged in live socket. Any re-wiring must be
carried out in accordance with the information detailed on thislabel.

As the colours of the wires in main leads may not correspondwith the colours marking identified in your plug/appliance,
proceed as follows:
The wire which is coloured Green & Yellow must be connected tothe Earth terminal marked with the letter E or by the earth symbol
or coloured Green or Green & Yellow.
The wire which is coloured Blue must be connected to theterminal which is marked with the letter N or coloured Blue or3

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POWER METERUSER MANUALUSER MANUAL

2. INTRODUCTION

3. SPECIFICATION

GPM-8212 Power Meter is a 16-bit CPU microprocessor equipped withmultifunction of full-digitized measurement, calibration and output. The
microprocessor has the advantage of high-speed sampling and calculation
function to accurately measure the distortion signal of waveform. Except for its
essential measurement on AC voltage, AC current, AC power, Power factor,and Frequency, the power meter also provides additional features of PT/CT
ratio setting, display value holding, the value of maximum and minimum
holding, range selecting, auto-ranging and etc.

VOLTAGE
Range
Measurement TypeInput Resistance
Maximum Input Voltage
PT Ratio Setting
Accuracy (at 23℃±5℃)(Sinewave)

The GPM-8212 is a low-cost, easy-to-use power measuring instrument.

±0.1% of reading±0.1% of range

CURRENTRange

In order for an even more efficient and convenient communication, thestandard RS232 or RS485 is available as an option attached to the instrument.

5.000V, 10.00V, 20.00V, 40.00V, 80.00V, 160.0V, 320.0V,
640.0V total 8 ranges by auto-range or manual.
True rms≧1MΩ
1000V(peak), 700V(rms)
1 to 9999

Measurement TypeInput Resistance
Maximum Input Current
CT Ratio setting
Accuracy(at 23℃±5℃)(Sinewave)

160.0mA, 320.0mA, 640.0mA, 1.280A, 2.560A, 5.120A,10.24A, 20.48A total 8 ranges by auto-range or manual.
True rms
0.01Ω
30A (peak), 20A (rms)
1 to 9999±0.1% of reading±0.1% of range

WATT
Range:
W A
160.0mA 320.0mA 640.0mA

1.280A

2.560A

5.120A

10.24A

20.48A

800.0mW 1.600W
1.600W 3.200W
3.200W 6.400W
6.400W 12.80W
12.80W 25.60W
25.60W 51.20W
51.20W 102.4W
102.4W 204.8W

6.400W
12.80W
25.60W
51.20W
102.4W
204.8W
409.6W
819.2W

12.80W
25.60W
51.20W
102.4W
204.8W
409.6W
819.2W
1.638kW25.60W
51.20W
102.4W
204.8W
409.6W
819.2W
1.638kW
3.276kW51.20W 102.4W
102.4W 204.8W
204.8W 409.6W
409.6W 819.2W
819.2W 1.638kW
1.638kW 3.276kW
3.276kW 6.553kW
6.553kW 13.10kW

V
5.000V
10.00V
20.00V
40.00V
80.00V
160.0V
320.0V
640.0V

Measurement TypeAccuracy(at 23℃±5℃)(Sinewave)

53.200W
6.400W
12.80W25.60W
51.20W
102.4W
204.8W
409.6W

True rms±0.2% of reading±0.2% of range

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POWER METERUSER MANUALUSER MANUAL

4. PANEL AND OUTLOOK INTRODUCTION
POWER FACTOR
Range
Computation
FREQUENCY
Measurement Range
Accuracy (23℃±5℃)
OPTION
Communication

0.001 to 1.000
W ÷ (V × A) = Power factor (PF)zFig 4.1 FRONT PANEL

40.0Hz to 400.0Hz±0.2% of reading±2 digits
RS-232, RS-485

GENERAL
Main Supply
Warm up time
Display
Minimum input
Response time
Overload indicating
Working temperature
Temperature coefficientAccessories
Dimension
WeighAC86~265V, 50/60Hz
30 minutes more.
A 4-digit 0.56" LED with 2 sets of 4-digit 0.4" LED.
2% of Range
2 cycles/sec“O.L”
0~50℃, RH＜80%±0.1% FS/℃
Instruction manual × 1, Power cord × 1， Disk × 1
250(W)×90(H)×281(D) m/m
Approx. 1.6 kgs

Note: The 1.0mm2 of cross-section dimension power cord should be used when thecurrent reaches to 10 Amperes, and use 2.0mm2 of cross-section dimension
power cord when the current reaches to 20 Amperes.

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POWER METERUSER MANUAL(5) Unit Indicator

4-1.Function Description(1) Remote Control Indicator
RMT

USER MANUALmW

Display Window 【1】Milliwatt indicator.

W

Display Window 【1】Watt indicator.

kW

Display Window 【1】Kilowatt indicator.

Remote Control Indicator(3) Status Indicator
RUN

When the instrument is working normal, the RUN
indicator is flashing stably, if not, it will be appeared
constant on or off.

(9) Unit & Status Indicator
HOLD

The HOLD indicator is on when press the key of
HOLD to maintain the display value not to be changedby any input.

MAXThe MAX indicator is on when press the key of MAX,the display then appears the maximum value it
obtained.

MINRATIO

V

Display Window 【2】Volt indicator.

kV

Display Window 【2】Kilovolt indicator.

PF

Display Window 【2】Power Factor indicator.

The MIN indicator is on when press the key of MIN,
the display then appears the minimum value it
obtained.

Hz

Display Window 【2】Hertz indicator.

The indicator is on when the value of PT and CT is set
to other value except 1.

mAA

9Display Window 【3】Milliampere indicator.

Display Window 【3】Ampere indicator.
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POWER METER

POWER METERUSER MANUALUSER MANUAL(8) Pushbuttons
kA

Display Window 【3】Kiloampere indicator.

LOCAL

Set up address for RS-458 interface only.

ADDRAuto

Display Window 【 2 】 Auto-range indicator. The․

Number key.

indicator is on when the window of voltage
measurement is set to auto-range. The voltage
measurement will be auto-ranged following the changeof external voltage.
Display Window 【 3 】 Auto-range indicator. TheBAUDRATE

Set interface baudrate with 1200, 2400, 4800 and9600 bps available for selection.

indicator is on when the window of current
measurement is set to auto-range. The current
measurement will be auto-ranged following the changeof external current.

5V PT

Number key.
Set PT Ratio range at 1~9999.

0

Number key.

A CT

Set CT Ratio range at 1~9999.

indicator is on when the input voltage peak is larger
than the measurement of voltage range.

6*If the Vpeak indicator is illustrated with manual
ranging, switch range by using △V button.
Window 【3】for current Peak indicator. The Apeak

MAXNumber key.
Set to the maximum value of the display, then press
the button again back to previous status.

Window 【2】for voltage Peak indicator. The Vpeak
Peakindicator is on when the input current peak is larger
than the measurement of current range.

1MIN*If the Apeak indicator is illustrated with manual
ranging, switch range by using △A button.
7V△

11

Number key.
Set to the minimum value of the display, then press
the button again back to previous status.

Number key.
Set the voltage range upward, press and hold thebutton for 2 seconds to enter autorange of voltage.
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POWER METERUSER MANUAL

2V▽

8A△

Number key.
Set the voltage range downward, press and hold thebutton for 2 seconds to enter autorange of voltage.

Number key.
Set the current range upward, press and hold thebutton for 2 seconds to enter autorange of voltage.

USER MANUAL

zFig. 4-2 REAR PANEL

RS232

CIRCUIT-BREAKER
PRESS
TO
RESET

SOURCE
N IN

3A▽

Number key.
Set the current range downward, press and hold thebutton for 2 seconds to enter autorange of current.

9Number key.

VSet Window 【2】to indicate Voltage function.

4Number key.

PF

Set Window 【2】 to indicate power factor function.

RS-232/RS-485
Interface Output

Current Breaker

AC 600V
MAXL IN

RS485

AUX-SOURCE

LOAD
LOUT

AC 86V~265V 50/60Hz

20A
MAX

NOUT

Input Terminal Board**Current Breaker: This is an Over-current protected component. Whenthe measurement is interrupted with over current input,
please reduce the measured load, then re-switch on, themeasurement can be back to normal.

Back key.
HzSet Window 【2】to indicate frequency function.

ENTEREnter key.

HOLD

Maintain the present display value.

13

Power Inlet

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POWER METERUSER MANUALUSER MANUAL

4-2.Wiringz

5. USAGE DESCRIPTION

Without PT or CT:zz

Baudrate setting
1) Press the button of Baud to appear the letter of BAUD on the window 2,window 3 indicates the previous setting parameters, and window 1
appears "————". If no further action, it will return to previous test
mode within 5 seconds, or press [Back] button directly.
2) Then proceed the following steps to set the desired parameters, such as
1200:— Press [1] to appear 1---.
— Press [2] to appear 12--.
— Press [0] to appear 120-.
— Press [0] to appear 1200.
3) If there is any mistake, press [Å] key to erase front error numbers.
4) After pressing [ENTER] to save the information, return to test mode.

With CTSOURCELOADWARNING: Make sure that the source power is off before anywiring connection.
WARNING: Make sure that all connecters are well connected
before the source power is on.

15z

Address setting
1) Press [Addr] to appear ADDR on the window 2, window 3 indicatesprevious setting parameters and window 1 appears "——". If no furtheraction, it will return to previous test mode within 5 seconds, or press[Back] button directly.
2) Then proceed the following steps to set the desired parameters, such as
10:— Press [1] to appear 1-.
— Press [0] to appear 10.
3) If there is any mistake, press [Å] key to erase front error numbers.
4) After pressing [ENTER] to save the information, return to test mode.

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POWER METERUSER MANUALUSER MANUAL

6. RS232 COMMUNICATION INTERFACEz PT Ratio setting
1) Press the button of [VPT] to appear the letters of PT on the window 2,window 3 indicates the previous setting parameter, and window 1
appears "————". If no further action, it will return to previous test
mode within 5 seconds, or press [Å] key directly.
2) Then proceed the following steps to set the desired parameters, such as
1000:— Press [1] to appear 1---.
— Press [0] to appear 10--.
— Press [0] to appear 100-.
— Press [0] to appear 1000.
3) If there is any mistake, press [Å] key to erase front error numbers.
4) After pressing [ENTER] to save the information, return to test mode.
zz Introduction
The instrument can be operated from a host (eg. A terminal controller,computer, PLC…) by sending commands through a computer interface on
the rear panel.
z Communication parameter
Baudrate : 1200, 2400, 4800, 9600 bps.
Parity: None
Data bits : 8
Stop bit:1
z Wire drawing： Located in the rear panel of GPM-8212.

CT Ratio setting
1) Press the button of [ACT] to appear the letters of CT on the window 2,window 3 indicates the previous setting parameters, and window 1appears "————". If no further action, it will return to previous test
mode within 5 seconds, or press [Å] key directly.
2) Then proceed the following steps to set the desired parameters, such as1000:— Press [1] to appear 1---.
— Press [0] to appear 10--.
— Press [0] to appear 100-.
— Press [0] to appear 1000.
3) If there is any mistake, press [Å] key to erase front error numbers.
4) After pressing [ENTER] to save the information, return to test mode

17RS-232

RS-485

Pin 232:
SIGNAL

CD RXD TXD DTR GND DSR RTS CTS

RI9 PIN25PIN
Pin 485:

18SIGNALNC

PIN No.

1233242057TxD TxD RxD RxD++234518667485922NC

NC

NC

NC

6789POWER METER

POWER METERUSER MANUALz

Communication command
COMMANDDESCRIPTION
F00
Data hold enable
F01
Data hold disable
F02
Set in maximum statusF03
Set in minimum status
F04
Set in normal statusR00
V Range=640.0V
R01
V Range=320.0V
R02
V Range=160.0V
R03
V Range=80.00V
R04
V Range=40.00VR05
V Range=20.00V
R06
V Range=10.00V
R07
V Range=5.000V
R08
A Range=20.48A
R09
A Range=10.24A
R10A Range=5.120A
R11A Range=2.560A
R12A Range=1.280A
R13
A Range=640.0mA
R14
A Range=320.0mA
R15
A Range=160.0mA
R16
V Range=Autorange
R17
A Range=Autorange
S00
Set Voltage Ratio(PT)S01
Set Current Ratio(CT)V00
Read Voltage
V01
Read Current
V02
Read Watt
V03
Read PF
V04
Read Hz19

USER MANUALz
EXAMPLE

DEMO Program; Demo program language: BASIC; Computer set Baudrate equal 9600, and use COM2; The GPM-8212 set Baudrate equal 9600; Command define in CMD$
10CMD$= “V00”
20VALUE$= “ ”
30OPEN “COM2:9600,N,8,,CS,DS,CD” FOR RANDOM AS#2 LEN=140FOR I= 1 TO 100
50PRINT #2, CMD$
60INPUT #2, VALUE$
70PRINT VALUE$
80NEXT I
90CLOSE #2100END

S00:1
S01:1

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POWER METERUSER MANUALUSER MANUAL

7. MAINTENANCE
7-2.Fuse Replacement Procedure
The following instructions are used by qualified person only to avoid
electrical shock, do not perform any service other than contained in theoperation instructions unless you are qualified to do so.

When you proceed calibration or maintenance of the Power Meter, if you
want to replace the fuse, the upper cover must be removed according to thefollowing steps:

7-1.Fuse Rating and type1).The handle must be turned downward 90 degrees first.

If the fuse is ruptured, the Power METER will not operate. Try todetermine and correct the cause of the blown fuse, then replace the fuse withcorrect rating and type shown as below:

MODEL
GPM-8212

FUSE Rating and Type
115V/230V
T0.5A 250VRating InputWatts
VA
22
28

WARNING: For continued fire protection, replace only with
250V fuse of the specified type and rating, and disconnect thepower cord before proceeding fuse replacement.

2122

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POWER METERUSER MANUAL

2).Pull apart the handle from the Power Meter. Please turn the handle left andright side slightly, that will make it easier to pull off the handle.

USER MANUAL

4).Please use a screwdriver to open the screw located at upper side of rear panel.
Therefore, the upper cover can pull toward the backside. In the meantime,the upper cover is moved.

3).There are two washers inside of two holes (the joints of handle and case)respectively. Please use a screwdriver to pry open these washers.

Note: If you want to install the upper cover, please reverse above steps.

7-3. Cleaning
To keep the instrument clean, wipe the case with a damp cloth and detergent. Do
not use abrasives or solvents.

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