Three Phase Meter

Three Phase Meter, purpose of the meter and its field of use is the execution of electromagnetic tests of transformers of all circuits and connection groups.

List of basic functions during single-phase and three-phase excitation of the tested transformer:

• current and idling loss measurement at low voltage;
• short-circuit resistance measurement;
• transformation ratio measurement;
• determination of connection groups of three-phase transformer windings and terminal polarity of single-phase transformers;
• measurement of DC copper resistance.

During the measurement, the asymmetry, the unsinusoidality and the excitation voltage frequency are controlled.
The function of the meter is maintenance, repair, setting-up, and testing of power transformers, both in laboratory and filed conditions by the services of ORGRES.

Three Phase Meter Technical specification

AC current measured range(three channels)¹, A, – 0.01-5.

AC voltage measured range (twin three-channel meter)², V, – 5-400.
Range of measured active power (three channels)^1,2, W, – 1-2000.
Measured frequency range, Hz, – 45-55.
Limits of current measurement , A, – 1,0; 5,0.
Limits of voltage measurement, V, – 100; 400.
Limits of resistance measurement, Ohm, – 0.001-100,0.
Basic reduced voltage measurement error at each limit, max., %, – 0.2.
Basic reduced power measurement error at cos(/_u, i) >= 0,8%, max., %, – 0,5.
Basic reduced current measurement error, max., %, – 0,2.
Absolute frequency measurement error, max., Hz, – 0,25.

Input resistance of voltage measurement channels, min., kOhm, – 600.
Load voltage drop of current strength measurement channels, max., mV, – 75.
Average service lifetime of the device, min., years, – 8.
Mean time to failure, min., h, – 10000.
The permissible auxiliary measurement error caused by the ambient air temperature change relative from normal to limiting values in the operating temperature range does not exceed the limit of permissible basic error.

Notes:¹ – without using an external current measuring transformer;² – without using an external voltage measuring transformer.

Definition: The meter which is used for measuring the power of three phase supply is known as the three phase energy meter. The three phase meter is constructed by connecting the two single phase meter through the shaft. The total energy is the sum of the reading of both the elements.