Short Circuit Test is Performed on Single Phase Transformer
Q. Explain how Short Circuit test is performed on single phase transformer.
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| S.C. Test on single phase transformer |
- This is mearly a short circuit test. Generally meters are connected in H .V. side to which a variable voltage can be applied with the help of a variac and L .V. winding is short circuited by a thick copper wire of a very low resistance.
- Reason for connecting H .V. side to supply and L.V. side shorted is that, only about 5 to 8 % of the rated voltage is required to circulate and rated currents in the windings and that voltage is easily available in the test – laboratory.
- This test may be carried out with the transformer out of its tank as voltage for testing is of small value (5 to 8 % of H .V. side).
- The supply voltage should have a standard frequency. The voltage applied to the H .V. winding shall be gradually increased with a variac (auto transformer) till the full load currents are circulated in the windings.
- Readings of Ammeter, voltmeter and wattmeter are recorded.
- The wattmeter reading gives the full load losses i.c. copper loss plus iron loss . But iron – loss can be neglected as a very small voltage is applied.
- Therefore wattmeter reading is treated as copper loss of primary and secondary windings of the transformer.