Mitsubishi Electric C70 Setup Manual page 596

Alarm No.
Power supply: Grounding
69
The motor power cable is in contact with FG (Frame Ground).
Investigation details
Measure the insulation across the power
1 cables (U,V,W) for all motors and the
ground. (Carry out a megger test.)
Has oil come in contact with the motor or
2
power cable?
3 Measure the insulation again.
Measure the resistance across the U, V, W
phase terminals of the servo/spindle drive
4 unit and the ground.
(Do not measure the insulation as the unit
could be damaged.)
Check whether there is any axis in which
5
alarm has occurred.
Alarm No.
Power supply: External contactor welding
6A
A contact of the external contactor is welding.
Investigation details
Check whether any alarm has occurred on
1
the drive unit side.
Check whether the contactor's contact has
2
melted.
Check that the contactor excitation wiring is
3 correctly connected from the power supply
unit's MC1 terminal.
Alarm No.
Power supply: Rush circuit error
6B
A thyristor for rush short circuit is ON when rushing.
Investigation details
Check whether any alarm has occurred on
1
the drive unit side.
2 Check the repeatability.
Check if there is any abnormality in the
3 unit's ambient environment.
(Ex. Noise, grounding, etc.)
Investigation results
Less than 100k . (Grounding)
100k or more. (Normal)
Oil has come in contact.
Oil has not come in contact.
Less than 1M . (Grounding)
1M or more. (Normal)
Less than 100k .
100k or more.
There is an axis in which alarm has
occurred.
There is no axis in which alarm has
occurred.
Investigation results
An alarm has occurred.
An alarm has not occurred.
The contactor has melted.
The contactor has not melted.
The connection is correct.
The connection is incorrect.
Investigation results
An alarm has occurred.
An alarm has not occurred.
The alarm occurs each time READY is
turned ON.
The alarm occurs occasionally.
Take remedies according to the causes of the abnormality in the ambient environment.
Appendix 2.16 Troubleshooting
Remedies
The motor or power cable may be ground
faulted.
Check the investigation item No. 2.
Take measures so that oil does not come in
contact. Check the motor's cannon
connector and the inside of the terminal box,
and clean as necessary.
Check the investigation item No. 3.
Replace the motor or cable.
Check the investigation item No. 2.
Replace the drive unit.
Replace the power supply unit.
Check the alarm No. "24" items.
Check the investigation item No. 2.
Remedies
Remove the cause of the alarm on the drive
side, and check the investigation item No. 2.
Check the investigation item No. 2.
Replace the contactor.
Check the investigation item No. 3.
Correctly connect.
Replace the power supply unit.
Remedies
Remove the cause of the alarm on the drive
side, and then carry out the investigation
details 2.
Check the investigation item No. 2.
Replace the unit.
Check the investigation item No. 3.
C70 Setup Manual
SV SP
CV
CV
579