Yaskawa Sigma-5 Large Capacity Users Manual: Design and Maintenance-Rotary Motors-Analog Voltage and Pulse Train Reference - Manual (Page 380)

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