YASKAWA E-V Series User Manual page 221

Alarm:
Alarm Name
A.C54:
External force was applied to the
Polarity Detection
servomotor.
Error 2
An encoder fault occurred.
A.C80:
Absolute Encoder
Clear Error
A SERVOPACK fault occurred.
(Multi-turn Limit Setting
Error)
Origin setting (Fn020) was not
executed correctly.
Contact fault of encoder connec-
tor or incorrect encoder wiring.
Encoder cable disconnection 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
A.C90:
Connector contact fault caused by
Encoder
vibration.
Communications Error
Malfunction caused by noise
interference.
A SERVOPACK fault occurred.
The noise interference occurred
on the input/output signal line
because the encoder cable is bent
and the sheath is damaged.
A.C91:
The encoder cable is bundled
Encoder
with a high-current line or near a
Communications
high-current line.
Position Data Error
The FG potential varies because
of influence from machines on
the servomotor side, such as the
welder.
Cause Investigative Actions
−
−
−
−
Check the encoder connector con-
tact status.
Check the encoder cable.
Check the operating environment.
−
−
Check the encoder cable and con-
nector.
Check the encoder cable layout.
Check the encoder cable layout.
8.1 Troubleshooting
Corrective Actions
Increase the value of the polarity
detection confirmation force refer-
ence (Pn495).
Increase the value of the polarity
detection allowable error range
(Pn498). Note that increasing the
allowable error will also increase
the motor temperature.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the servomotor may be
faulty. Repair or replace the servo-
motor.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Repair or replace the SER-
VOPACK.
Turn the power supply OFF and
then ON again. Then execute origin
setting (Fn020).
Re-insert the encoder connector and
confirm that the encoder is correctly
wired.
Use the encoder cable with the
specified rating.
Improve the operating environmen-
tal conditions, and replace the cable.
If the alarm still occurs, repair or
replace the SERVOPACK.
Correct the wiring around the
encoder to avoid noise interference
(Separate the encoder cable from
the main circuit cable, improve
grounding, etc.)
Connect the servomotor to another
SERVOPACK, and turn ON the
control power. If no alarm occurs,
the SERVOPACK may be faulty.
Repair or replace the SERVO-
PACK.
Confirm that there is no problem
with the encoder cable layout.
Confirm that there is no surge volt-
age on the encoder cable.
Properly ground the device to sepa-
rate from the encoder FG.
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