The heat run test of a transformer without its loading is performed by means of

The correct answer is 'option 4'

Solution:

Sumpner's Test

• It is a non-loading heat run test on transformers.
• The maximum rise in the temperature in a large transformer is determined by the full load test by measuring the temperature of their oil after every particular interval of time.
• The full load test on a small transformer is very convenient but on a large transformer, it is very difficult.
• While performing this test, the amount of power consumed is equal to the sum of the copper and iron losses of both transformers at full loading.
• This test is also known as back to back test. Two identical transformers are used in this test.