YASKAWA E-V-MD Series User Manual page 272

10 Maintenance, Inspections, and Troubleshooting
10.2.2 Troubleshooting of Alarms
Alarm Number:
Alarm Name
(Alarm Description)
A.C92:
Encoder
Communications
Timer Error
A.CA0:
Encoder Parameter
Error
A.Cb0:
Encoder Echoback
Error
A.CC0:
Multiturn Limit
Disagreement
A.d00:
Position Error
Overflow
(Position error exceeded
the value set in the
excessive position error
alarm level (Pn520).)
10-12
Cause
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.
An encoder fault occurred.
The wiring and contact for
encoder cable are incorrect.
Noise interference occurred due
to incorrect cable specifications
of encoder cable.
Noise interference occurred
because the wiring distance for
the encoder cable is too long.
The FG potential varies because
of influence from machines on
the servomotor side, such as the
welder.
Excessive vibration and shocks
were applied to the encoder.
An encoder fault occurred.
The multiturn limit value of the
encoder is different from that of
the SERVOPACK. Or, the multi-
turn limit value of the SERVO-
PACK has been changed.
The servomotor U, V, and W wir-
ings is faulty.
The position reference speed is
too high.
The acceleration of the position
reference is too high.
Setting of the excessive position
error alarm level (Pn520) is low
against the operating condition.
A SERVOPACK fault occurred.
Investigative Actions
−
Check the operating environment.
−
−
Check the wiring.
−
−
Check the cable layout for encoder
cable.
Check the operating environment.
−
Check the value of the PnA48 of the
SERVOPACK.
Check the servomotor main circuit
cable connection.
Reduce the reference speed, and
operate the SERVOPACK.
Reduce the reference acceleration,
and operate the SERVOPACK.
Check the alarm level (Pn520) to
see if it is set to an appropriate
value.
−
(cont'd)
Corrective Actions
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 servomotor
may be faulty. Replace the servo-
motor.
Correct the wiring.
Use tinned annealed copper
shielded twisted-pair or screened
unshielded twisted-pair cable with a
2
core of at least 0.12 mm .
The wiring distance must be 10 m
max.
Properly ground the machines to
separate from encoder FG.
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.
Execute Fn013 at the occurrence of
alarm.
Confirm that there is no contact
fault in the motor wiring or encoder
wiring.
Reduce the position reference speed
or acceleration of position refer-
ence. Or, reconsider the electronic
gear ratio.
Reduce the reference acceleration
of the position reference using a
MECHATROLINK command, or
smooth the acceleration of the posi-
tion reference by selecting the posi-
tion reference filter (ACCFIL)
using a MECHATROLINK com-
mand.
Set the Pn520 to proper value.
Restart the SERVOPACK. If the
alarm still occurs, the SERVO-
PACK may be faulty. Replace the
SERVOPACK.