Sumpner’s test is conducted on transformers to determine:
- Temperature
- Stray losses
- All-day efficiency
- None of the above
Correct answer: 1. Temperature
Sumpner’s test is conducted on transformers to determine temperature effects.
Sumpner‟s test also know as back to back test is conducted by connecting two transformers in parallel across a single rated voltage supply. In Sumpner’s test the two secondary windings are connected in series
with opposing polarity.
Generally Sumpner’s test is employed for large transformers becuase for large sized transformers the ordinary full-load tests are way too expensive from the viewpoint of electrical energy consumption alongside difficulties in finding a suitable load. The thermal tests require operation under full load for many hours. This difficuly is resolved using Sumpner’s test.