
B-65382EN/02 MAINTENANCE 2.CHECKING ELECTRIC CHARACTERISTICS
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2.1 CHECKING INSULATION RESISTANCE
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 coil slider.
CAUTION
If a voltage is kept applied to the motor at the time
of insulation resistance measurement, the
insulation of the motor can degrade. Make an
insulation resistance measurement in a shortest
possible time.
2.2 CHECKING WINDING RESISTANCE
By using a milliohm meter, make a winding resistance measurement
as described below. Insulate those terminals that are not used for
measurement. For winding resistance values, see Part I,
"SPECIFICATIONS".
- Measure the resistance values between U and V, V and W, and
W and U of the coil slider.
- Check that the variations among measured values are within
±1%.
- Check that each measured value is within ±5% of two times the
resistance value described in Part I, "SPECIFICATIONS".
If a resistance value not satisfying the above is measured, replace the
coil slider immediately.
NOTE
1 For a linear motor based on the terminal
specification, detach the power line, and make a
measurement at the terminal.
2 For a linear motor based on the power line
specification, make a measurement at the tip of the
power line (lead on the motor side).