8 Troubleshooting
8.2.2 Troubleshooting of Warnings
8-24
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 SigmaJu, etc.
Change the regenerative resistance,
regenerative resistor capacity, SER-
VOPACK capacity, or converter
capacity. Reconsider the operating
conditions using the capacity selection
software SigmaJu, etc.
Regenerative power
continuously flowed
back because negative
load was continuously
applied.
Check the load to the servomotor
during 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
multi-winding drive
unit.
−
The multi-winding drive unit may be
faulty. Replace the multi-winding
drive unit.
A.94A
Data Setting
Warning 1
(Parameter Num-
ber Error)
Disabled parameter
number was used.
Refer to
8.3 Monitoring Communica-
tion Data on Occurrence of an Alarm
or Warning
to determine which
command was the cause of the
warning.
Use the correct parameter number.
A.94B
Data Setting
Warning 2
(Out of Range)
Attempted to send val-
ues outside the range to
the command data.
Refer to
8.3 Monitoring Communica-
tion Data on Occurrence of an Alarm
or Warning
to determine which
command was the cause of the
warning.
Set the value of the parameter within
the allowable range.
A.94C
Data Setting
Warning 3
(Calculation Er-
ror)
Calculation result of set
value is incorrect.
Refer to
8.3 Monitoring Communica-
tion Data on Occurrence of an Alarm
or Warning
to determine which
command was the cause of the
warning.
Set the value of the parameter within
the allowable range.
(cont’d)
Warning Num-
ber: Warning
Name (Warning
Description)
Cause
Investigative Actions
Corrective Actions