Mitsubishi Electric MELDAS MDS-B Series Instruction Manual page 186

Absolute position fluctuation:
Alarm No.
A fluctuation exceeding the tolerable value was detected in the absolute position
93
detected when the CNC power is turned ON.
Investigation details
1 Wiggle the connectors by hand to check
whether the detector connectors (unit
side and detector side) are
disconnected.
2 Turn the power OFF, and check the
connection of the detector cables with a
tester.
3 Check the repeatability.
Carry out zero point return again.
4 Connect with another normal axis unit
and check whether the fault is on the
unit side.
5 Check if there is any abnormality in the
unit's ambient environment.
(Ex. Ambient temperature, noise,
grounding)
CAUTION
Chapter 11 Troubleshooting
Investigation results
The connector is disconnected (or
loose).
The connector is not disconnected.
There is a connection fault.
The connection is normal.
The alarm is not repeated.
The alarm is always repeated.
Or, the state returns to normal once, but
then is repeated sometimes.
The alarm is on the unit side.
The alarm occurs even when the unit is
replaced.
No abnormality is found in particular.
An abnormality was found in the
ambient environment.
To prevent trouble, when changing the motor and driver combination, avoid
driving a driver with a larger capacity than the specified driver using the motor.
The motor could be demagnetized. Note that this combination can be used for
checking in the emergency stop state. The motor can be driven with a driver
with a capacity smaller than the specifications.
Correctly install.
Investigate item 2.
Replace the communication cable.
Investigate item 3.
If no abnormality is found with
investigation item 5, continue use.
Investigate item 4.
Replace the drive unit.
Investigate item 5.
Replace the motor (detector).
Take remedies according to the causes of
the abnormality.
Ex.
temperature ...
cooling
11–30
Alarm check timing
f1 f2
–
Remedies
High
Check the
fan.
Incomplete grounding .... Additionally
ground.
f3 f4
– –