Troubleshooting Of Warnings - YASKAWA Sigma-V Series User Manual

8.2.2 Troubleshooting of Warnings

Refer to the following table to identity the cause of a warning and the action to be taken. Contact your
Yaskawa representative if the problem cannot be solved by the described corrective action.
Warning Num-
ber: Warning
Name (Warning
Description)
The servomotor U, V,
and W wirings is faulty.
The multi-winding
drive unit gain is too
low.
The acceleration of the
position reference is too
A.900:
high.
Position Error
Overflow
Setting of the excessive
position error alarm
level (Pn520) is low
against the operating
condition.
A fault occurred in the
multi-winding drive
unit.
When the servomotor
A.901:
power is ON, the posi-
Position Error
tion error exceeded the
Overflow Alarm
parameter setting
at Servo ON
(Pn526×Pn528/100).
Incorrect wiring or con-
tact fault of servomotor
and encoder.
Operation beyond the
overload protection
A.910:
characteristics.
Overload
Excessive load was
(Warning before
applied during opera-
alarm A.710 or
tion because the servo-
A.720 occurs)
motor was not driven
due to mechanical prob-
lems.
A fault occurred in the
multi-winding drive
unit.
Abnormal vibration was
detected at the motor
speed.
A.911:
The moment of inertia
Vibration
ratio (Pn103) value is
greater than the actual
value or is greatly
changed.
Cause Investigative Actions
Check the servomotor main circuit
cable connection.
Check the multi-winding drive unit
gain to see if it is low.
Reduce the reference acceleration, and
operate the SERVOPACK.
Check the alarm level (Pn520) to see
if it is set to an appropriate value.
−
−
Check the wiring.
Check the motor overload characteris-
tics and executed run command.
Check the executed operation refer-
ence and motor speed.
−
Check for abnormal noise from the
servomotor, and check the speed and
torque waveforms during operation.
Check the moment of inertia ratio.
8.2 Warning Displays
Corrective Actions
Confirm that there is no contact fault
in the motor wiring or encoder wiring.
Increase the servo gain by using the
function such as advanced autotuning.
Reduce the reference acceleration of
the position reference using a
MECHATROLINK command, or
smooth the acceleration of the position
reference by selecting the position ref-
erence filter (ACCFIL) using a
MECHATROLINK command.
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.
Set an appropriate value for the exces-
sive position error warning level at
servo ON (Pn528).
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 multi-winding drive unit may be
faulty. Replace the multi-winding
drive unit.
Reduce the motor speed or reduce the
servo gain by using the function such
as one-parameter tuning.
Set the moment of inertia ratio
(Pn103) to an appropriate value.
8
8-23