
3. TROUBLESHOOTING
AND ACTION TROUBLESHOOTING B-65165E/02
- 130 -
3.2.2 IPM Alarms (8., 9., A., b., C., d., and E in the LED display; note
these codes are displayed simultaneously with a period.)
(1) Wait for about 10 minutes. Then release the emergency stop state.
If an IPM alarm still occurs, go to (2).
If the cause is IPM overheat, the IPM alarm will not recur. IPM
overheat can occur if the ambient temperature is high or the motor
is overloaded. Check the operating condition.
(2) Remove the power wires from the amplifier terminals, and release
an emergency stop state.
If the IPM alarm does not recur, go to (3).
If the IPM alarm recurs, the probable cause is the operation of the
IPM protective function (for overcurrent or power failure).
Replace the amplifier and see.
→ If the IPM does not recur, go to (3).
(3) Check for insulation between PE and each of the removed power
wires U, V, and W. If insulation is perfect, go to (4). If not,
disconnect the power wires from the motor connector. Then
check for insulation between PE and each of the U, V, and W
terminals on the motor.
→ If there is a short-circuit between PE and U, V, or W of the
motor, replace the motor.
→ If insulation is perfect, replace the power wires.
(4) Connect the power wires. Attach the check board (A06B-6071-
K290) to connector JX5 to measure the waveform of the actual
current (IR and IS) in the servo amplifier module. Accelerate or
decelerate the motor, and measure the actual current (IR and IS) of
the amplifier.
If an overcurrent alarm occurs right after an emergency stop state
is released, go to (5).
Release an emergency stop state, and start the motor.
Check whether the waveform of the actual current (IR and IS) is a
normal sine wave.
→ If normal, go to (5).
→ If not, replace the amplifier.
(5) Check whether there is noise on the actual current (IR and IS)
waveform.
→ If there is no noise, replace the amplifier.
→ If there is noise, use a shielding wire, and ground the
shielding, or take other countermeasures as required.
(6) If still there is noise, a probable cause is a defective command
cable or a hardware failure in the CNC.