YASKAWA Sigma-V Series User Manual page 267

8 Troubleshooting
8.1.2 Troubleshooting of Alarms
Alarm Number:
Alarm Name
(Alarm Description)
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).)
8-18
Cause
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.
A fault occurred in the multi-
winding drive unit.
The multiturn limit value of the
encoder is different from that of
the multi-winding drive unit. Or,
the multiturn limit value of the
multi-winding drive unit has been
changed.
A fault occurred in the multi-
winding drive unit.
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 fault occurred in the multi-
winding drive unit.
Investigative Actions
Check the wiring.
−
−
Check the cable layout for encoder
cable.
Check the operating environment.
−
−
Check the value of the Pn205 of the
multi-winding drive unit.
−
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
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 50 m
max.
Properly ground the machines to
separate from encoder FG.
Reduce the machine vibration or
correctly install the servomotor.
Turn the control power supply OFF
and ON again. If the alarm still
occurs, the servomotor may be
faulty. Replace the servomotor.
Turn the control power supply OFF
and ON again. If the alarm still
occurs, the multi-winding drive unit
may be faulty. Replace the multi-
winding drive unit.
Execute Fn013 at the occurrence of
alarm.
Turn the main circuit power supply
of the converter OFF and ON again.
If the alarm still occurs, the multi-
winding drive unit may be faulty.
Replace the multi-winding drive
unit.
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.
Turn the control power supply OFF
and ON again. If the alarm still
occurs, the multi-winding drive unit
may be faulty. Replace the multi-
winding drive unit.