YASKAWA SGDV series User Manual page 311

9 Troubleshooting
9.1.2 Troubleshooting of Alarms
Alarm Number:
Alarm Name
(Alarm Description)
A.C80:
Absolute Encoder
Clear Error and
Multi-turn Limit Set-
ting Error
A.C90:
Encoder
Communications Error
A.C91:
Encoder
Communications
Position Data Error
A.C92:
Encoder
Communications
Timer Error
9-16
Cause
An encoder fault occurred.
A fault occurred in the SERVO-
PACK.
Contact fault of connector or
incorrect wiring for encoder
cable.
Cable disconnection for encoder
cable or short-circuit.
Or, incorrect cable impedance.
Corrosion caused by improper
temperature, humidity, or gas,
short-circuit caused by intrusion
of water drops or cutting oil, or
connector contact fault caused by
vibration.
Malfunction caused by noise
interference.
A fault occurred in the SERVO-
PACK.
Noise interference occurred on
the I/O signal line because the
encoder cable is bent and the
sheath is damaged.
The encoder cable is bundled
with a high-current line or near a
high-current line.
The FG potential varies because
of influence from machines on
the servomotor side, such as the
welder.
Noise interference occurred on
the I/O signal line from the
encoder.
Excessive vibration and shocks
were applied to the encoder.
An encoder fault occurred.
A fault occurred in the SERVO-
PACK.
Investigative Actions
−
−
Check the connector contact status
for encoder cable.
Check the encoder cable.
Check the operating environment.
−
−
Check the encoder cable and con-
nector.
Check the cable layout for encoder
cable.
Check the cable layout for encoder
cable.
−
Check the operating environment.
−
−
(cont'd)
Corrective Actions
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the servomotor may be
faulty. Replace the servomotor.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.
Re-insert the connector and confirm
that the encoder is correctly wired.
Use the cable with the specified rat-
ing.
Improve the operating environmen-
tal conditions, and replace the cable.
If the alarm still occurs, replace the
SERVOPACK.
Correct the wiring around the
encoder by separating the encoder
cable from the servomotor main cir-
cuit cable or by checking the
grounding and other wiring.
Connect the servomotor to another
SERVOPACK, and turn ON the
control power. If no alarm occurs,
the SERVOPACK may be faulty.
Replace the SERVOPACK.
Confirm that there is no problem
with the cable layout.
Confirm that there is no surge volt-
age on the cable.
Properly ground the machines to
separate from the encoder FG.
Take countermeasures against noise
for the encoder wiring.
Reduce the machine vibration or
correctly install the servomotor.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the servomotor may be
faulty. Replace the servomotor.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.