What is a Megger tester used for?

What is a Megger tester used for?

The Megger insulation tester is a small, portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. For good insulation, the resistance usually reads in the megohm range.

How do you test a ground with a Megger?

If you are testing insulation resistance to ground, place the positive probe on the ground wire or the grounded metal junction box and the negative probe on the conductor or terminal. Energize the Megger for 1 minute. Read the value of the resistance at the end of the minute test and note it in your table.

How does a Megger measure resistance?

The Megger insulation tester is essentially a high-range resistance meter (ohmmeter) with a built-in direct-current generator. ... This current (usually at an applied voltage of 500 volts or more) is measured by the ohmmeter, which has an indicating scale.

How do I know if my Megger is working?

Clamp the alligator clip on one of the megger probes to the wire or cable, touch the other probe to the exposed conductor and press the test button. The megger will generate a current between the probes, and the meter will record the resistance of the jacket to the flow of the current.

What is the purpose of insulation resistance test?

An insulation resistance (IR) test measures the total resistance between any two points separated by electrical insulation. The test, therefore, determines how effective the dielectric (insulation) is in resisting the flow of electrical current.

What is IR value in electrical?

IR Value for Transformer. Insulation resistance tests are made to determine insulation resistance from individual windings to ground or between individual windings. Insulation resistance tests are commonly measured directly in megohms or may be calculated from measurements of applied voltage and leakage current.

What is IR testing?

An insulation resistance (IR) test measures the total resistance between any two points separated by electrical insulation. ... Such tests are useful for checking the quality of insulation, not only when a product is first manufactured but also over time as the product is used.

What is earth Megger?

The earth megger is essentially a direct reading ohmmeter and it has a hand driven generator which supplies the testing current. The ohmmeter essentially consists of two coils (current coil and pressure coil) mounted at a fixed angle to each other on a common axis.

What is infinity in Megger?

If your megohmmeter is reading "OL" (over load) or "I" (infinity), these are commonly used readings on megohmmeters when the measurement exceeds the maximum indicated value of the tester.

What is a good Megger reading?

Anything reading between 2 megohms and 1000 megohms is usually considered a good reading, unless other problems have been noted. Anything less than 2 megohms indicates an insulation problem.