Yaskawa Sigma-5 User Manual: Design and Maintenance - Rotary Motors - Analog Voltage and Pulse Train Reference - Manual (Page 370)

10.2 Warning Displays
10-23
10
Trou
blesh
ooting
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 external
regenerative resistance,
regenerative resistor
capacity, or SERVO-
PACK 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, or SER-
VOPACK capacity. Reconsider the
operating conditions using the capac-
ity selection software SigmaJunma-
Size+, 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 SERVOPACK fault
occurred.
−
The SERVOPACK may be faulty.
Replace the SERVOPACK.
A.930:
Absolute Encod-
er 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 SERVOPACK fault
occurred.
−
The SERVOPACK may be faulty.
Replace the SERVOPACK.
A.941:
Change of Pa-
rameters Re-
quires 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