YASKAWA SGDH User Manual page 554

10 Inspection, Maintenance, and Troubleshooting
10.1.6 Troubleshooting of Alarm and Warning
Alarm
Alarm Name
Display
A.Cb
Encoder
Echoback Error
A.CC
Multiturn Limit
Disagreement
A.d0
Position Error
Pulse Overflow
(In servo ON sta-
tus, the position
error pulses
exceed the over-
flow level set in
the parameter
Pn505.)
Table 10.6 Alarm Display and Troubleshooting (Cont'd)
Situation at Alarm
Occurrence
Occurred when the The encoder wiring and contact are incorrect.
control power sup-
Noise interference occurred due to incorrect encoder
ply was turned ON
cable specifications.
or during operation.
Noise interference occurred because the wiring dis-
tance for the encoder cable is too long.
Noise interference occurred on the signal line,
because the encoder cable is bent and the sheath is
damaged.
The encoder cable is bundled with a high-current
line or near a high-current line.
The FG electrical potential varies because of the
influence from such machines on the servomotor
side as welders.
Noise interference occurred on the signal line from
the encoder.
Excessive vibration and shocks to the encoder was
applied.
An encoder fault occurred.
A SERVOPACK board fault occurred.
Occurred when the The parameter settings for the SERVOPACK are
control power sup- incorrect.
ply was turned ON.
The multiturn limit value for the encoder is not set or
was changed.
Occurred during A SERVOPACK board fault occurred.
normal operation.
Occurred when the The overflow level (Pn505) is incorrect.
control power sup-
A SERVOPACK board fault occurred.
ply was turned ON.
Occurred at the ser- The contact in the servomotor U, V, and W wirings
vomotor high-speed is faulty.
rotation.
A SERVOPACK board fault occurred.
The servomotor did Wirings of the servomotor U, V, and W are incorrect.
not run with posi-
A SERVOPACK board fault occurred.
tion reference input.
Normal movement, The SERVOPACK gain adjustment is improper.
but occurred with a
long distance refer-
The V-REF input voltage and the Pn300 setting are
ence input.
incorrect.
The position reference pulse frequency is too high.
Setting of the position error pulse overflow alarm
level (Pn505) is incorrect.
The servomotor specifications do not meet the load
conditions such as torque and moment of inertia.
Cause
10-14
Corrective Actions
Correct the encoder wiring.
Use tinned annealed copper twisted-pair or
twisted-pair shielded wire with a core of at least
2 2
0.12 mm (0.0002 in ).
The wiring distance must be 20m (65.6 ft) max.
Correct the encoder cable layout.
Correct the encoder cable layout so that no surge
is applied.
Ground the machine separately from PG side FG.
Take measures against noise for the encoder wir-
ing.
Reduce the machine vibration or mount the servo-
motor securely.
Replace the servomotor.
Replace the SERVOPACK.
Correct the setting of Pn205 (0 to 65535).
Execute Fn013 at the occurrence of alarm.
Replace the SERVOPACK.
Make the value set in the Pn505 to other than 0.
Replace the SERVOPACK.
Correct the servomotor wiring.
Correct the encoder wiring.
Replace the SERVOPACK.
Correct the servomotor wiring.
Replace the SERVOPACK.
Increase the speed loop gain (Pn100) and position
loop gain (Pn102).
Lower the reference speed to the speed limit
value.
Adjust slowly the position reference pulse fre-
quency.
Apply the smoothing function.
Correct the electronic gear ratio.
Set the parameter Pn505 to proper value.
Reconsider and correct the load and servomotor
capacity.