
B-65285EN/03 MOTOR MAINTENANCE 1.SERVO MOTOR MAINTENANCE
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If you find anything unusual in relation to the above items <1> to
<3>, contact your FANUC service staff.
(3) Winding and insulation resistances.
Measure heck its winding and insulation resistances.
Note that extremely severe inspections (such as dielectric strength
tests) of a motor may damage its windings. For the winding
resistances of motors, refer to FANUC AC SERVO MOTOR
αis/αi series Descriptions (B-65262EN), or ask FANUC. For
insulation resistances, see the following table.
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
100MΩ 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.
NOTE
If the insulation resistance steeply drops within a
short period of time, it is likely that liquid such as
cutting liquid may have entered from the outside.
Check the drip-proof environment again (by referring
to Section 2.1, "USE ENVIRONMENT FOR SERVO
MOTORS," in Chapter I in "FANUC AC SERVO
MOTOR αis/αi series Descriptions (B-65262EN)).