Motor Insulation Resistance Test Iec Standard

Testing and inspection environmental measurements laboratory instrumentation power and energy.

Motor insulation resistance test iec standard.

The graph below shows an example of the insulation resistance readings on an electric motor. As per ie rules 1956. 1k v 1 mω minimum 1kv 1 mω 1kv. See the site fixed equipment for measurement and testing of electrical networks energy management and optimization systems.

At a pressure of 1000 v applied between each live conductor and earth for a period of one minute the insulation resistance of hv installations shall be at least 1 mega ohm or as specified by the bureau of indian standards. The measurement of insulation resistance is a common routine test performed on all types of electrical wires and cables. Reverse side of card at right is used to record the test data. Ground insulation test of a motor.

Curve b shows same values corrected to 20 c see page 22 giving a definite downward trend toward an unsafe condition. Based upon equipment rating. Figure 4 typical record of insulation resistance of a mill motor. Figure 3 typical scale on the megger insulation tester.

During the measurement and immediately afterwards some of the terminals carry dangerous voltages and must not be touched. Cables for rated voltages of 1 kv um 1 2 kv and 3 kv um 3 6 kv reference number iec 60502 1 2004 e international standard iec 60502 1 second edition 2004 04. At a the insulation resistance decreases due to aging and dust accumulation. The measurement of insulation resistance is carried out by means of a megohmmeter high resistance range ohmmeter this is how the test works.

Curve a shows test values as measured. 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. At c the fault has been repaired rewinding of the motor so the insulation resistance has returned to. 1 magnet wire at high stress in air voids b.

Power cables with extruded insulation and their accessories for rated voltages from 1 kv um 1 2 kv up to 30 kv um 36 kv part 1. The results obtained from ir test are not intended. Portable measurement equipment in a wide variety of fields. One meg ohm rule for ir value for equipment.

The intent of the iec standard is to specify test methods that assure a given stator insulation design can prevent formation of pd in new windings and continue to suppress pd throughout the life of the motor type i insulation. 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. The sharp fall at b indicates there was an insulation fault.