Yaskawa Sigma-5 Large Capacity Users Manual: Design and Maintenance-Rotary Motors-Mechatrolink-II Communication Reference - Manual (Page 327)

9 Troubleshooting
9.1.2 Troubleshooting of Alarms
9-16
A.C10:
Servo Overrun
Detected
(Detected when the
servomotor power is
ON.)
The order of phases U, V, and W
in the servomotor wiring is incor-
rect.
Check the motor wiring.
Confirm that the servomotor is cor-
rectly wired.
An encoder fault occurred. −
If the alarm still occurs after turning
the power OFF and then ON again,
even though the servomotor is cor-
rectly wired, the servomotor may be
faulty. Replace the servomotor.
A fault occurred in the SERVO-
PACK or converter.
−
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK or con-
verter may be faulty. Replace the
SERVOPACK or converter.
A.C80:
Absolute Encoder
Clear Error and
Multi-turn Limit Set-
ting Error
An encoder fault occurred. −
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the servomotor may be
faulty. Replace the servomotor.
A fault occurred in the SERVO-
PACK.
−
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.
A.C90:
Encoder
Communications Error
Contact fault of connector or
incorrect wiring for encoder
cable.
Check the connector contact status
for encoder cable. Re-insert the connector and confirm
that the encoder is correctly wired.
Cable disconnection for encoder
cable or short-circuit.
Or, incorrect cable impedance.
Check the encoder cable.
Use the cable with the specified rat-
ing.
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.
Check the operating environment.
Improve the operating environmen-
tal conditions, and replace the cable.
If the alarm still occurs, replace the
SERVOPACK.
Malfunction caused by noise
interference.
−
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.
A fault occurred in the SERVO-
PACK.
−
Connect the servomotor to another
SERVOPACK, and turn ON the
control power. If no alarm occurs,
the SERVOPACK may be faulty.
Replace the SERVOPACK.
A.C91:
Encoder
Communications
Position Data Error
Noise interference occurred on
the I/O signal line because the
encoder cable is bent and the
sheath is damaged.
Check the encoder cable and con-
nector. Confirm that there is no problem
with the cable layout.
The encoder cable is bundled
with a high-current line or near a
high-current line.
Check the cable layout for encoder
cable. Confirm that there is no surge volt-
age on the cable.
The FG potential varies because
of influence from machines on
the servomotor side, such as the
welder.
Check the cable layout for encoder
cable. Properly ground the machines to
separate from the encoder FG.
(cont’d)
Alarm Number:
Alarm Name
(Alarm Description)
Cause Investigative Actions Corrective Actions