
B–65235EN/02
SAFETY PRECAUTIONS (FANUC AC SERVO MOTOR series)
11
MOTOR INSULATION RESISTANCE MEASUREMENT
Measure an insulation resistance between each winding and motor frame using an insulation
resistance meter (500 VDC). Judge the measurements according to the following table.
Insulation resistance Judgment
100 MΩ or higher Acceptable
10 to 100 MΩ The winding has begun deteriorating. There is no
problem with the performance at present. Be sure to
perform periodic inspection.
1 to 10 MΩ The winding has considerably deteriorated. Special
care is in need. Be sure to perform periodic
inspection.
Lower than 1 MΩ Unacceptable. Replace the motor.