After the required connections are made you apply the test voltage for a period of one min.
Transformer insulation resistance test values.
Calculation of winding temperature at the end of temperature rise test of transformer.
Insulation resistance test of transformer is divided into three parts.
That this document list how to test specific pieces of equipment or systems.
Calculation of the i 2 r losses in transformer.
Use the megger test at a low voltage side.
Within those sections there are typically three main bodies of information.
Apply the test voltage and note the reading.
In the factory it helps in determining the following.
Megger insulation resistance test device.
Insulation resistance decreases in temperature or moisture.
Adjust megger tester at 1000 v dc.
1 insulation resistance ir this is the simplest of the tests.
Value at 60 seconds after application of the test voltage is referred to as the insulation resistance of the transformer at the test temperature.
Apply the test voltage and note the reading.
Values based on ieee std 43 2013.
The transformer neutral bushing is to be disconnected from earth during the test.
A rated line to line voltage for three phase ac machines line to ground voltage for single phase machines and rated direct voltage for dc machines or field windings.
Steps of this test.
Visual and mechanical inspection 2.
Value at 60 seconds after application of the test voltage is referred to as the insulation resistance of the transformer at the test temperature.
Use caution when testing.
The transformer neutral bushing is to be disconnected from earth during the test.
Expected test results section 7 consists of sections specific to each particular type of equipment.
B kv is the rated machine terminal to terminal voltage.
Ansi neta mts 2015 table 100 11 insulation resistance test values rotating machinery for one minute at 40 c.
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.
Basically there are three different tests that can be done using a megohmmeter.
The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
Clean the terminals of the transformer.
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.
