RATIO TEST....

Q. What is the need of doing ratio test?
A. We will check the ratio according to manufacture specification.

PROCEDURE:
1. Remove all external connections.
2. Short the secondary winding.
3. Inject 25% of rated primary current by using auto transformer and loading transformer.
4.Note down the secondary current by using leakage current tester.
5. Check the ratio by dividing primary current by secondary current.
6. Repeat the same procedure for 50% , 75%  , 100% of primary current.
7. Repeat the same test for different tappings.
8. Discharge the charge after completion of test.