Siemens YASKAWA 840DI Maintenance Manual page 52

3.2 Errors without alarm display and troubleshooting
Table 3.1 Errors without alarm display (cont'd)
Malfunction
Spindle Motor and The earth ground of
Servomotor generates
Motor or Drive Units is
unusual noise or wrong.
vibration.
The encoder cable
affected by noise.
Drive machine data have
wrong value.
The motor is not
mounted securely.
There is something
abnormal on the bearing
or rotor.
Coupling or centering
between machine and
motor is not precise.
Machine has source of
vibration or insufficient
strength.
Foundation bolts is
loosened.
Cause Check point
Check connection to
ground for motor and
Drive Unit.
• Check separation of
encoder signal and
power line.
• Check grounding
shield of encoder
cable.
Check if twisted pair
cable with shield is used
for encoder wiring.
Compare current value
of drive machine data
with setting list.
Check looseness of
mounting.
Check the noise and
vibration around the
bearing during
independent operation of
the motor.
Check misalignment and
imbalance of coupling.
Check the movable part
of machine for any
foreign matters, damage,
deformation and/or
source of vibration.
Check the looseness of
foundation bolts.
3-6
Remedy
Ground securely.
Arrange the encoder
cable suitably.
Replace cable.
Correct drive machine
data.
Retighten the fixing
screw.
Replace the motor.
Adjust the alignment or
balance of coupling.
Contact maintenance
stuff or machine tool
builder.
Retighten the foundation
bolts.