
B–65152E/03
SAFETY PRECAUTIONS
11
Measuring the insulation resistance of the motor
Measure the insulation resistance between the windings and frame, using a megohmmeter (500
VDC). Determine the state from the following table:
Insulation resistance Judgment
Greater than 100 MΩ Satisfactory
10 to 100 MΩ The motor has started to deteriorate. Performance is not affected but10 to 100 M
The motor has started to deteriorate. Performance is not affected but
periodic inspection is required.
1 to 10 MΩ The motor has deteriorated to a degree where performance may be1 to 10 M
The motor has deteriorated to a degree where erformance may be
adversely affected. Periodic inspection is required.
Less than 1 MΩ Defective. Replace the motor.