Mitsubishi MELDAS MDS-C1 Instruction Manual page 277

Ground fault
Alarm No.
The motor power cable is contacting FG (ground).
69
Investigation details
1 Measure the insulation across the U,
V, W phase cables for all motors and
the ground. (Carry out a megger
test.)
2 Has oil come in contact with the
motor or power cable?
3 Measure the insulation again.
4 Measure the resistance across the U,
V, W phase terminals of the
servo/spindle drive unit and the
ground.
(Do not measure the insulation, as
the unit could be damaged.)
External contactor melting
Alarm No.
The external contactor's contact has melted.
6A
Investigation details
1 Check whether any alarm has
occurred on the drive unit side.
2 Check whether the contactor's
contact has melted.
3 Check that the contactor excitation
wiring is correctly connected from the
power supply unit's MC1 terminal.
Rush relay melted
Alarm No.
The rush resistance short-circuit relay does not turn OFF.
6B
Investigation details
1 Check whether any alarm has
occurred on the drive unit side.
2 Check the repeatability.
3 Check if there is any abnormality in
the unit's ambient environment.
(Ex. Noise, grounding)
6. Troubleshooting
Investigation results
100kΩ or less.
100kΩ or more.
Oil has come in contact.
Oil has not come in contact.
1MΩ or less.
1MΩ or more.
100kΩ or less.
100kΩ or more.
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.
No abnormality is found in particular.
The grounding is incomplete.
An alarm will occur easily if another
device operates.
6 - 32
Remedies
The motor or power cable may be
ground faulted.
Investigate item 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.
Investigate item 3.
Replace the motor or cable.
Investigate item 2.
Replace the drive unit.
Replace the power supply unit.
Remedies
Remove the cause of the alarm on
the drive side, and then carry out the
investigation details 2.
Investigate item 2.
Replace the contactor.
Investigate item 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.
Investigate item 2.
Replace the unit.
Investigate item 3.
Replace the unit.
Take remedies according to the
causes of the abnormality.
Ex. Incomplete grounding:
Additionally ground.
Noise: Noise measures for
other devices.
CV CR
CV CR
CV CR