11-18
11-4 Troubleshooting
OMNUC G5-SERIES AC SERVOMOTOR AND SERVO DRIVE USER'S MANUAL
11
Error and Maintenance
The motor holding
brake is
ineffective.
Power is supplied to the
holding brake.
Check whether power is supplied to
the holding brake.
Configure a circuit that cuts
power supply to the holding brake
when the motor stops and the
load is held by the holding brake.
The motor does not
stop or is hard to stop
even if the operation
command (RUN) is
turned OFF while the
motor is rotating.
The load inertia is too large. Check the following:
• Is the load too large?
• Is the motor rotation speed too high?
Review the load conditions, and
replace the Servomotor and Servo
Drive with appropriate models.
The stop circuit failed.
−
Replace the driver.
The motor is
producing unusual
noises or the
machine is
vibrating.
(Continued on next
page)
There are problems with the
machine's installation.
Check whether the Servomotor's
mounting screws are loose.
Retighten the mounting
screws.
Check whether the axes are
misaligned in the coupling.
Align the coupling.
Check whether the coupling is unbalanced. Adjust the coupling's balance.
There is a problem with the
bearings.
Check for noise or vibration around
the bearings.
Contact your OMRON dealer
or sales office.
The gain is wrong.
−
Perform manual tuning.
The Speed Feedback Filter
Time Constant (Pn??) is wrong.
Check the set value of Pn??.
Return the set to 0 (default
set) or increase the set value.
Noise is entering the control I/O
signal cable because the cable
does not meet specifications.
Check that it is a twisted-pair wire or
twisted-pair shielded cable with core
wires that are at least 0.08 mm
2
.
Use control I/O signal cable
that meets specifications.
Noise is entering the control I/O
signal cable because the cable is
longer than the specified length.
Check the length of the control I/O
signal cable.
Shorten the control I/O signal
cable to 3 m or less.
Noise is entering the cable
because the encoder cable
does not meet specifications.
Check that it is a twisted-pair
shielded cable with core wires that
are at least 0.12 mm
2
.
Use encoder cable that meets
specifications.
Noise is entering the encoder
cable because the cable is
longer than the specified length.
Check the length of the encoder
cable.
Shorten the encoder cable to
less than 50 m.
Noise is entering the signal lines
because the encoder cable is
stuck or the sheath is damaged.
Check the encoder cable for
damage.
Correct the encoder cable's
pathway.
Too much noise is entering
the encoder cable.
Check whether the encoder cable is
bound together with or too close to
high-current lines.
Install the encoder cable
where it won't be subjected to
surges.
The FG's potential is
fluctuating due to devices
near the Servomotor, such
as welding machines.
Check for ground problems (loss of
ground or incomplete ground) at
equipment such as welding
machines near the Servomotor.
Ground the equipment
properly and prevent currents
from flowing to the encoder
FG.
Errors are being caused by
excessive vibration or shock
on the encoder.
There are problems with mechanical
vibration or motor installation (such
as the precision of the mounting
surface, attachment, or axial offset).
Reduce the mechanical
vibration or correct the
Servomotor's installation.
Symptom
Probable cause
Items to check
Measures