Mitsubishi Electric MDS-B-SPJ2 Series Specification Manual page 167

(4) The start time was long, or became longer than before.
Investigation items
1 Check whether the
friction torque has
increased.
2 Rotate the motor by
hand and check
whether the bearing is
normal.
3 Check whether a
torque limit signal is
being input.
(5) The motor stops during cutting.
Investigation items
1 Check the load
amount during cutting.
2 Investigate as in item
(4) above, and carry
out the appropriate
measures.
11. Troubleshooting
Investigation results
The friction torque has increased.
No particular problem.
The motor does not rotate smoothly.
The motor rotates smoothly.
The signal is being input.
The signal is not being input.
Investigation results
The load meter jumps above 120%
during cutting.
No particular problem.
11 − 23
Remedy
Correct the machine side.
Investigate item 2, and carry out the
appropriate measures.
Replace the spindle motor.
Investigate item 3, and carry out the
appropriate measures.
Set so it is not input.
Replace the unit.
Remedy
Decrease the load.
Investigate item 2, and carry out the
appropriate measures.