Motor Insulation Resistance Test Procedure Pdf

Insulation resistance testing purpose.

Motor insulation resistance test procedure pdf.

Motor so the insulation resistance has returned to a higher value and has remained stable over time indicating a good conition. Insulation resistance decreases in temperature or moisture. An insulation spot test is an insulation resistance test that can be used to verify the condition of the insulation over the life of the motor. Insulation resistance test insulation resistance failure of an electric motor is one of the first signs that the motor is about to fail.

During the measurement and immediately afterwards some of the terminals carry dangerous voltages and must not be touched. At c the insulation resistance value after the motor has been rewound. The measurement of insulation resistance is carried out by means of a megohmmeter high resistance range ohmmeter this is how the test works. 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.

Curve indicates a e potential problem. Curve d indicates a good insulation with an excellent polarization index of 5. When performing insulation resistance testing you must maintain consistency. 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.

Loss of insulation resistance of an electric motor is one of the first signs of motor failure. It is commonly used in the industry for acceptance testing prior to energizing the cable and for maintenance testing programs. The test should also be performed after a motor is. Smaller systems will remain steady because the capacitive and absorption currents drop to zero faster than on larger systems.

Larger insulation systems will show a steady decrease. 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. Set the voltage. A spot test should be performed at reg ular intervals every six months for ex ample to track the changes in insulation integrity.

The megger insulation tester is a small portable instrument that gives you a direct reading of insulation resistance in ohms or megohms. The test measures the insu lation resistance between the phases and or between phase and ground. Insulation resistance testing is a non destructive test procedure. Dc voltage of 500 or 1000 v is applied between the windings and the ground of the motor.

Ground insulation test of a motor. 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. After 1 min you should read and record the resistance value.