YASKAWA SGDV User Manual page 271

9 Troubleshooting
9.1.2 Troubleshooting of Alarms
Alarm Number:
Alarm Name
(Alarm Description)
A.C90:
Encoder
Communications Error
A.C91:
Encoder
Communications
Position Data Error
A.C92:
Encoder
Communications
Timer Error
A.CA0:
Encoder Parameter
Error
9-12
Cause
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 SERVOPACK fault occurred.
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 SERVOPACK fault occurred.
An encoder fault occurred.
A SERVOPACK fault occurred.
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
Re-insert the connectors and con-
firm that the encoder is correctly
wired.
Use the cables with the specified
rating.
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 cables.
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.
Restart the SERVOPACK. If the
alarm still occurs, the servomotor
may be faulty. Replace the servo-
motor.
Restart the SERVOPACK. If the
alarm still occurs, the SERVO-
PACK may be faulty. Replace the
SERVOPACK.
Restart the SERVOPACK. If the
alarm still occurs, the servomotor
may be faulty. Replace the servo-
motor.
Restart the SERVOPACK. If the
alarm still occurs, the SERVO-
PACK may be faulty. Replace the
SERVOPACK.