[67_Open Phase]; [68_Watchdog]; [69_Ground Fault] - Mitsubishi Electric -MR-CV User Manual

[67_Open phase]

• An open phase occurred in the main circuit power supply of the converter unit.
Cause
1.
An open phase occurred in the main circuit power
supply of the converter unit.
2.
The converter unit has malfunctioned.

[68_Watchdog]

• The CPU or other component parts have malfunctioned.
Cause
1.
The converter unit has malfunctioned.

[69_Ground fault]

• The servo motor has a ground fault.
Cause
1.
The servo motor power cable has a ground fault
or has shorted.
2.
The servo motor has a ground fault.
3.
The drive unit and servo amplifier have
malfunctioned.
4.
The converter unit has malfunctioned.
8 CONVERTER UNIT TROUBLESHOOTING
78
8.3 Handling methods for alarms/warnings
Check/action method
Check that the main circuit power line is connected with the converter unit.
Check if the main circuit power line of the converter unit is closed. If the main circuit
power line of the converter unit is open, replace the main circuit power line.
Replace the converter unit, then check the repeatability.
Check/action method
Replace the converter unit, then check the repeatability.
Check/action method
Check if the servo motor power cable has a ground fault. If the servo motor power
cable has a ground fault, correct the wiring.
Check if the servo motor power cable has shorted. If the servo motor power cable
has shorted, replace the servo motor power cable.
After disconnecting the connector on the servo motor side of the servo motor power
cable, check the insulation between phases (U/V/W/E). If the servo motor has a
ground fault or has shorted, replace the servo motor.
Check if this alarm occurs while the connector on the drive unit and servo amplifier
side of the servo motor power cable is disconnected. If the alarm occurs, replace the
drive unit and servo amplifier.
Replace the converter unit, then check the repeatability.