Mitsubishi Electric MDS-B-SPJ2 Series Specification Manual page 169

(8) The rotation does not stabilize.
Investigation items
1 Check the spindle
parameter (SP022:
VGNP1, SP023:
VGNI1) setting values.
2 Jiggle the speed
detector connector
(spindle drive unit side
and speed detector
side) to see whether it
is coming loose.
3 Turn the power OFF,
and check the speed
detector cable
connection with a
tester. (Especially
check the shield
wiring.)
4 Investigate the wiring
and installation
environment.
1) Are the units
correctly grounded?
2) Are there any
devices that
produce noise
around the units?
11. Troubleshooting
Investigation results
The rotation stabilizes when both
setting values are raised 2-fold.
The rotation does not stabilize when
the values are changed as shown
above.
Connector came (was coming) loose. Install correctly.
Connectors are normal.
The connection is faulty, or there is a
broken wire.
The connection is normal.
1) The grounding is incomplete.
2) The alarm occurs easily when a
specific device is operated.
No particular problem.
11 − 25
Remedy
Change the setting values. Note that
the gear sound may become louder.
Return the settings to the original
values. Investigate item 2, and carry
out the appropriate measures.
Investigate item 3, and carry out the
appropriate measures.
Replace the detector cable. Correctly
connect the cable.
Investigate item 4, and carry out the
appropriate measures.
Correctly ground the units.
Execute noise countermeasures for
the device at the left.
Replace the spindle drive unit.