
1. MAINTENANCE OF SERVO MOTOR
B--65245EN/02
MAINTENANCE OF
SERVO MOTOR
170
(4) Insulation resistance check
Measure the insulation resistance between the motor winding and
motor frame, using a megohmmeter (500 VDC). Determine whether
the insulation resistance is satisfactory according to the standards
listed below:
Insulation resistance Judgment
100Mτ or higher The insulation is satisfactory.
10 to 100Mτ The insulation has started to degrade. The degrada-
tion has not yet adversely affected the performance.
Before starting operation, however, always check the
insulation for further degradation. Alternatively,
replace the motor.
1to10Mτ The insulation has degraded substantially. Extreme
care is necessary. Before starting the operation,
always check the insulation for further degradation.
Alternatively, replace the motor.
Upto1Mτ The insulation is unacceptable. Replace the motor.
(5) Observation of t orque command (TCMD) waveform and velocity
command (VCMD) waveform
Using an oscilloscope, display a normal voltage waveform. Compare
the normal waveform with that observed at the periodic check.
The waveform varies with the load, feedrate, and other conditions.
Compare t he waveforms observed under identical conditions (rapid
traverse at a reference position return, low--s peed feed, for example).
For details of the observation, see Appendix E, ”Servo C heck Board.”
(6 ) Heat check
Check whether the motor has overheated during operation. Check the
temperature of the motor surface by using a thermolabel or some other
means.
WARNING
The motor surface may reach temperatures as high as 80C
under some operating conditions. Do not touch the motor.