Turn Ratio Tester

The Three-phase Transformer Turns Ratio Tester TRT series are specially designed for turns ratio, phase shift and excitation current measurement of power, distribution and instrument transformers.

The TRT03 devices generate single-phase test voltage while TRT30, TRT33 and TRT63 devices generate both single-phase and true three-phase test voltages.

When generating a single-phase excitation voltage, the TRT supplies in turn single-phase excitation test voltage to each of the three transformer primary windings. The induced voltages across each of the corresponding unloaded transformer windings are then measured; the ratio of these voltages is calculated and shown on the display. It is repeated for all three phases.

When generating true three phase voltage, the TRT generates and outputs a true three-phase excitation test voltage to the three transformer primary windings. The induced three phase voltage across the unloaded transformer windings are measured and the transformer turns ratio is calculated.


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