YASKAWA Sigma-V Series User Manual page 380

10 Troubleshooting
10.2.2 Troubleshooting of Warnings
Warning Num-
ber: Warning
Name (Warning
Description)
A.911:
Vibration
A.920:
Regenerative
Overload
(Warning before
the alarm A.320
occurs)
A.921:
Dynamic Brake
Overload
(Warning before
the alarm A.731
occurs)
A.930:
Absolute
Encoder Battery
Error
(The absolute
encoder battery
voltage is lower
than the specified
value.)
∗ Only when an
absolute encoder
is connected.
A.941:
Change of
Parameters
Requires Restart
10-24
Cause
Abnormal vibration was Check for abnormal noise from the
detected at the motor servomotor, and check the speed and
speed. torque waveforms during operation.
The moment of inertia
ratio (Pn103) value is
greater than the actual Check the moment of inertia ratio.
value or is greatly
changed.
The power supply volt-
age exceeds the speci- Measure the power supply voltage.
fied limit.
Insufficient regenera-
tive resistance, regener-
ative resistor capacity,
Check the operating condition or the
SERVOPACK capacity,
capacity using the capacity selection
or converter capacity.
Software SigmaJunmaSize+, etc.
Or, regenerative power
has been continuously
flowing back.
Regenerative power
continuously flowed
Check the load to the servomotor dur-
back because negative
ing operation.
load was continuously
applied.
The servomotor rotates
because of external Check the operation status.
force.
The rotating energy at a Check the power consumed by DB
DB stop exceeds the DB resistance (Un00B) to see how many
resistance capacity. times the DB has been used.
A fault occurred in the
−
SERVOPACK or con-
verter.
The battery connection
Check the battery connection.
is incorrect.
The battery voltage is
lower than the specified Measure the battery voltage.
value 2.7 V.
A fault occurred in the
−
SERVOPACK.
Parameters that require
−
the restart have been
changed.
Investigative Actions
(cont'd)
Corrective Actions
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.
Set the power supply voltage within
the specified range.
Change the regenerative resistance,
regenerative resistor capacity, SER-
VOPACK capacity, or converter
capacity. Reconsider the operating
conditions using the capacity selection
software SigmaJunmaSize+, etc.
Reconsider the system including servo
drives, machine, and operating condi-
tions.
Take measures to ensure the servomo-
tor will not rotate because of external
force.
Reconsider the following:
• Reduce the motor reference speed.
• Reduce the moment of inertia ratio.
• Reduce the number of times of the
DB stop operation.
The SERVOPACK or converter may
be faulty. Replace the SERVOPACK
or converter.
Reconnect the battery.
Replace the battery.
The SERVOPACK may be faulty.
Replace the SERVOPACK.
Turn OFF the power and ON again.