PEWM-3A
THREE-PHASE ENERGY STANDARD CLASS 0.05

Application and brief description

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.

Standard Equipment Set

• Four safety cables for voltage
• RS 232 cable
• Four alligator clips
• Scanning head with mechanics
• Six current cables for 120A
• Hand switch
• Six current cables for 12A
• Cable for auxiliary supply
• Three current clamps
• Thermal printer (option)

Mode “Error”

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:

• two-, three-, or four- wire measurement
• active / reactive / apparent energy measurement
• delivery of pulses from scanning head or manually (with functional button)
• register verification

The device indicates error of the electricity meter in [%] and the true value of energy. The delivery of pulses is traced with a bargraph.

Mode “Phase shift measurement”

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.

Mode “Power”

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.

Mode “Harmonics”

The harmonic content of each input signal of voltage or current can be measured in this mode.

Mode “Oscilloscope”

Two signals in real time are drawn on the graphic display. The operator selects the signals.

Mode “Save of the measurements”

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:

• Printing of protocol
• Organization of archive file
• Search of data from the archive

Mode “Thermal printer”

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.

Mode “PC”

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.

Technical data

Errors and ranges

Notes:
* 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).

Safety and Electromagnetic compatibility

SAFETY TESTS:
EN 61010-1 (Transient over voltage category ІІІ, Degree of pollution 2)
EMC TESTS:
EN 61010-4-2, EN 61000-4-4, EN 61000-4-5, EN 61000-4-6
Functionality according to:
IEC 60736