YASKAWA E-V Series User Manual page 311

9 Troubleshooting
9.1.2 Troubleshooting of Alarms
Alarm:
Alarm Name
A.CA0:
Encoder Parameter
Error
A.Cb0:
Encoder Echoback
Error
A.d00:
Position Error Pulse
Overflow
(Position error exceeded
the value set in the
excessive position error
alarm level (Pn520))
9-18
Cause
An encoder fault occurred.
A SERVOPACK fault occurred.
The encoder wiring and contact
are incorrect.
Noise interference occurred due
to incorrect encoder cable specifi-
cations.
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.
A SERVOPACK fault occurred.
The contact in the servomotor U,
V, and W wirings is faulty.
The SERVOPACK gain is low.
The frequency of the position ref-
erence pulse is too high.
The position reference accelera-
tion is too fast.
Setting of the Pn520 (Excessive
Position Error Alarm Level) is
low against the operating condi-
tion.
A SERVOPACK fault occurred.
Investigative Actions
−
−
Check the encoder wiring.
−
−
Check the encoder cable and con-
nector.
Check the operating environment.
−
−
Check the motor main circuit cable
connection.
Check the SERVOPACK gain to see
if it is too low.
Reduce the reference pulse fre-
quency, and operate the SERVO-
PACK.
Reduce the reference acceleration,
and operate the SERVOPACK.
Check the alarm level (Pn520) to
see if it is set to an appropriate
value.
−
Corrective Actions
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.
Correct the encoder wiring.
Use tinned annealed copper twisted-
pair or shielded twisted-pair cable
with a core of at least 0.12 mm
The wiring distance must be 20 m
max.
Make the grounding for the
machine separately from encoder
side FG.
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. 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.
Confirm that there is no contact
fault in the motor wiring of encoder
wiring.
Increase the servo gain using the
parameters such as Pn100 and
Pn102.
Reduce the position reference pulse
frequency or reference accelera-
tion. Or, reconsider the electronic
gear ratio.
Apply the smoothing function, such
as using position reference accelera-
tion/deceleration time constant
(Pn216).
Set the Pn520 to proper value.
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.
2
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