YASKAWA Sigma-V Series User Manual page 261

8 Troubleshooting
8.1.2 Troubleshooting of Alarms
Alarm Number:
Alarm Name
(Alarm Description)
A.510:
Overspeed
(The servomotor speed
exceeds the maximum.)
A.511:
Overspeed of Encoder
Output Pulse Rate
A.520:
Vibration Alarm
A.710:
A.720:
Overload
A.710: High Load
A.720: Low Load
8-12
Cause
The order of phases U, V, and W
in the servomotor wiring is incor-
rect.
A reference value exceeding the
overspeed detection level was
input.
The motor speed exceeded the
maximum.
A fault occurred in the SERVO-
PACK or converter.
The encoder output pulse fre-
quency exceeded the limit.
The encoder output pulse output
frequency exceeded the limit
because the motor speed was too
high.
Abnormal vibration was detected
at the motor speed.
The moment of inertia ratio
(Pn103) value is greater than the
actual value or is greatly
changed.
Incorrect wiring or contact fault
of servomotor and encoder.
Operation beyond the overload
protection characteristics.
Excessive load was applied
during operation because the ser-
vomotor was not driven due to
mechanical problems.
A fault occurred in the SERVO-
PACK or converter.
Investigative Actions
Check the motor wiring.
Check the input value.
Check the motor speed waveform.
−
Check the encoder output pulse set-
ting.
Check the encoder output pulse out-
put setting and motor speed.
Check for abnormal noise from the
servomotor, and check the speed
and torque waveforms during oper-
ation.
Check the moment of inertia ratio.
Check the wiring.
Check the servomotor overload
characteristics and executed run
command.
Check the executed operation refer-
ence and motor speed.
−
(cont'd)
Corrective Actions
Confirm that the servomotor is cor-
rectly wired.
Reduce the reference value or adjust
the gain.
Reduce the speed reference input
gain, adjust the servo gain, or recon-
sider the operating conditions.
The SERVOPACK or converter
may be faulty. Replace the SERVO-
PACK or converter.
Decrease the setting of the encoder
output pulse (Pn212).
Decrease the motor speed.
Reduce the motor speed or reduce
the speed loop gain (Pn100).
Set the moment of inertia ratio
(Pn103) to an appropriate value.
Confirm that the servomotor and
encoder are correctly wired.
Reconsider the load conditions and
operating conditions. Or, increase
the motor capacity.
Remove the mechanical problems.
The SERVOPACK or converter
may be faulty. Replace the SERVO-
PACK or converter.