Because electrical insulation will exhibit dynamic behavior during the course of your test.
Motor insulation resistance test.
The measurement of insulation resistance is carried out by means of a megohmmeter high resistance range ohmmeter this is how the test works.
Ground insulation test of a motor.
The insulation keeps the current flowing along the wire exactly as intended.
During the measurement and immediately afterwards some of the terminals carry dangerous voltages and must not be touched.
Using insulation testing with an instrument such as the fluke 1555 10 kv insulation tester combined with fluke connect technology such leaks can be detected as insulation resistance slowly tapers over time a sign of normal and expected deterioration.
A if the insulation resistance of a new cleaned or repaired motor that has been stored for some time is less then 10 mω the reason might be that the windings are humid and.
Loss of insulation resistance of an electric motor is one of the first signs of motor failure.
For a three phase motor insulation resistance is usually measured between each motor winding or phase and between each motor phase and motor frame earth using an insulation tester or megger.
Whether the dielectric is good or bad.
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.
The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms.
For a three phase motor the isolation resistance can usually be measured between each motor winding or phase and between each motor stage and motor frame earth by an insulation tester or megger 4.
1 insulation resistance ir this is the simplest of the tests.
Regular checks of motor insulation resistance the key to prolonging the life of any electrical device is periodic checks maintenance the insulation resistance of stored and active motors should be checked regularly.
When performing insulation resistance testing you must maintain consistency.
Insulation resistance decreases in temperature or moisture.
Insulation resistance test insulation resistance failure of an electric motor is one of the first signs that the motor is about to fail.
Set the voltage.
Basically there are three different tests that can be done using a megohmmeter.