Insulation Resistance Test Procedure Of Current Transformer

Before conducting a transformer winding resistance test it is important to observe all safety warnings and take proper precautions ensure that all equipment to be tested is properly grounded and treat all high voltage power equipment as energized until proven otherwise by using the proper lockout tagout procedures.

Insulation resistance test procedure of current transformer.

Adjust megger tester at 1000 v dc. Leakage current should be as small as possible therby ir value should be as high as possible r v i. The insulation resistance test is of value for future comparison and also for determining if the transformer is to be subjected to the applied voltage test the winding insulation resistance test is a dc high voltage test used to determine the dryness of winding insulation system the test measures the insulation resistance from individual windings to. Required equipment for testing.

Insulation resistance test of transformer is divided into three parts. It is carried out as a type test as well as routine test. Clean the terminals of the transformer. Insulation resistance is the ratio of the applied voltage dc to the total leakage current.

Isolation required for the test. The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. Use the megger test at a low voltage side. This test can be repeated during the service life of the transformer and verified against the result obtained during manufacturing as a check to determine if the insulation is malfunctioning or decaying.

With a little record keeping and common sense however you can get a good picture of the insulation condition from values that are only relative. Insulation resistance decreases in temperature or moisture. Megger insulation resistance test device. Go to content 3.

Verify nameplate ratings are in accordance with the approved drawings and. Transformer winding resistance measurement is carried out to calculate the i 2 r losses and to calculate winding temperature at the end of a temperature rise test. It is also done at site to ensure healthiness of a transformer that is to check loose connections broken strands of conductor high contact resistance in tap changers high. Measure insulation resistance between low voltage windings and the main body of the transformer.

Variac step up transformer 0 2kv primary current injection set. Steps of this test.