Question

The insulation resistance test is performed using a/an:

1. Ammeter
2. Megger
3. Galvanometer
4.  Voltmeter

Answer 1

Correct Answer - Option 2 : Megger

• The megger is known as an insulation tester.
• Megger is a portable instrument to measure high insulation resistances.
• It works on the principle of electromagnetic induction.
• The electrical power to a megger is provided by a permanent magnet D.C. generator.
• The test voltages are usually of order 500, 1000, or 2500 V are generated by hand-driven generator (permanent magnet D.C. generator).
• The operation of a megger is based on moving coil meter.
• Earth pit resistance is measured with an earth tester, also called earth megger which can test the resistance across a range of currents and distances.
• Insulation megger is used to measure the insulation resistance of the cables.
• Frequency meter is used for measuring the unknown frequency of a signal. The frequency meter consists of one inductive and one resistive coil.
• When the frequency of the signal varies from standard frequency, the current distribution across the coils becomes changes.
• The wattmeter is an instrument used for the measurement of power.