The three-phase standard PEWM-3A is used for a precise test of all types of electricity meters on site. The current can be measured via direct connection in two ranges (up to 12A or to 120A). Measurements with current clamps to 100A are also possible. The current clamps are electronically compensated.
The accuracy class of PEWM-3A is 0.05 for direct measurement of voltage, current and power; class 0.2 for current clamps.
The revolutions or the pulses from the electricity meter are counted with a universal scanning head or manually with the help of a functional button. Error of the electricity meter is determined for active, reactive or apparent energy; 2-wire, 3-wire or 4-wire connection. The registers of the electricity meter can be tested too.
The display of vector diagram and the numerical values of current, voltage and phase shift help the operator to detect circuit faults.
Other functions of the device are power, phase shift and harmonic measurement; drawing of the waveforms.
200 measurements can be stored in a non-volatile memory. The measurements can be printed on a thermal printer, connected to the RS232C output, or transferred to a computer. The unit can be remotely controlled by a PC.
The Vector diagram of the three – phase load is drawn on the large graphic display in this mode. The true RMS values of voltage and current, the angle between them, the frequency and the sequence of rotation are also indicated. This mode can be switched for three – wire or four– wire measurement.
The constant of the electricity meter, the number of revolutions (pulses) and the measurement mode are preset by the operator with the help of the buttons.
Measurement mode is selected out of the following:
The device indicates error of the electricity meter in [%] and the true value of energy. The delivery of pulses is traced with a bargraph.
The phase angle between two voltages and between voltage and current are indicated in this mode. The power factor of the three phases is also displayed.
The values of active, reactive and apparent power of the three phases are indicated. This mode can be switched for three-wire or four-wire measurement.
The harmonic content of each input signal of voltage or current can be measured in this mode.
Two signals in real time are drawn on the graphic display. The operator selects the signals.
The results of 200 measurements can be stored in a non-volatile memory and transferred to a computer via RS 232C. The following data are stored: number of the electricity meter, the current, voltage and power factor values of the three – phases, error of the electricity meter, circuit type. The PC program works under Windows 98, XP, Vista and has the following features:
The thermal printer is connected to the RS232C output of the unit. Whenever a save function is performed, the saved information will also be printed, if the printer is powered on.
The unit can be remotely controlled by a PC and together with a phantom load can be used as an automatic testing system for one electricity meter.
|Power supply||45V ÷ 480Vac|
|Power consumption||15VА max|
|Operation temperature||– 10°C ÷ + 50°C|
|Relative humidity||< 90% non condensing|
|Frequency range||45 ÷ 65 Hz|
|Pulse output||100 000 imp/ kWh (kVarh)|
|Graphic LCD, back lit display||160 x 128 pixels|
|Dimensions||406 x 330 x 174 mm|
|Degree of protection||IP 42 (opened case);
IP 65 (closed case)
|Voltages measurement (phase-neutral)||± 0.05 [%] *||10V ÷ 300V (overburden up to 500V)|
|Current measurement (direct to 120A)||± 0.05 [%] *||0.50А ÷ 120.00А|
|± 0.05 [%] **||0.05А ÷ 0.49А|
|Current measurement (direct to 12A)||± 0.05 [%] *||0.05А ÷ 12.00А|
|± 0.05 [%] **||0.01А ÷ 0.05А|
|Current measurement with 100A current clamps||± 0.2 [%] *||0.200А ÷ 100.00А|
|± 0.2 [%] **||0.020А ÷ 0.199А|
|Power / energy measurement (direct to 120A)||± 0.05 [%] *||0.50А ÷ 120.00А|
|± 0.05 [%] **||0.05А ÷ 0.49А|
|Power / energy measurement (direct to 12A)||± 0.05 [%] *||0.05А ÷ 12.00А|
|± 0.05 [%] **||0.001A ÷ 0.05А|
|Power / energy measurement (current clamps)||± 0.2 [%] *||0.200A ÷ 100.00A|
|± 0.2 [%] **||0.01A ÷ 0.199A|
|Frequency||0.01Hz||45Hz ÷ 65Hz|
|Phase-shift||0.01°||0.0° ÷ 359.99°|
|Temperature coefficient||0.0015% / °C||0°C ÷ 40°C|
* Error related to the measured value.
** Error related to the maximum value of the range.
All power / energy errors are related to apparent power (to be divided by power factor).
EN 61010-1 (Transient over voltage category ІІІ, Degree of pollution 2)
EN 61010-4-2, EN 61000-4-4, EN 61000-4-5, EN 61000-4-6
Functionality according to: