10.2 Alarm Displays
10-9
10
Maintenance, Inspections, and
T
roubleshooting
A.520:
Vibration Alarm
Abnormal vibration was detected
at the motor speed.
Check for abnormal noise from the
servomotor, and check the speed
and torque waveforms during oper-
ation.
Reduce the motor speed or reduce
the speed loop gain (PnAC2).
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.521:
Autotuning Alarm
(Vibration was
detected while
executing the one-
parameter tuning,
EasyFFT, or tuning-
less function.)
The servomotor vibrated consid-
erably while performing tuning-
less function.
Check the motor speed waveform.
Reduce the load so that the moment
of inertia ratio falls within the
allowable value, or raise the load
level using the tuning-less levels
setting or reduce the rigidity level.
The servomotor vibrated consid-
erably during one-parameter tun-
ing or EasyFFT.
Check the motor speed waveform.
Check the operation procedure of
corresponding function and take a
corrective action.
A.710:
A.720:
Overload
A.710: High Load
A.720: Low Load
Incorrect wiring or contact fault
of servomotor and encoder.
Check the wiring.
Confirm that the servomotor and
encoder are correctly wired.
Operation beyond the overload
protection characteristics.
Check the servomotor overload
characteristics and executed run
command.
Reconsider the load conditions and
operating conditions. Or, increase
the motor capacity.
Excessive load was applied
during operation because the ser-
vomotor was not driven due to
mechanical problems.
Check the executed operation refer-
ence and motor speed.
Remove the mechanical problems.
A.7A3:
Control Board
Overheat
The surrounding air temperature
of the SERVOPACK is too high.
Measure the surrounding air tem-
perature of the SERVOPACK.
Improve the installation conditions
of the SERVOPACK to reduce the
surrounding air temperature.
A.810:
Encoder Backup Error
(Only when an
absolute encoder is
connected.)
(Detected on the
encoder side.)
Alarm occurred when the power
to the absolute encoder was ini-
tially turned ON.
Check to see if the power was
turned ON initially.
Set up the encoder.
The encoder cable disconnected,
and connected again.
Check to see if the power was
turned ON initially.
Confirm the connection and set up
the encoder.
The power from both the control
power supply (+5 V) from the
SERVOPACK and the battery
power supply is not being sup-
plied.
Check the encoder connector bat-
tery or the connector contact status.
Replace the battery or take similar
measures to supply power to the
encoder, and set up the encoder.
An absolute encoder fault
occurred.
−
If the alarm cannot be reset by set-
ting up the encoder again, replace
the servomotor.
A.820:
Encoder Checksum
Error
(Detected on the
encoder side.)
An encoder fault occurred.
−
• Absolute encoder
Set up the encoder again using
Fn008. If the alarm still occurs,
the servomotor may be faulty.
Replace the servomotor.
• One-turn absolute encoder or
incremental encoder
The servomotor may be faulty.
Replace the servomotor.
A.830:
Absolute Encoder
Battery Error
(The absolute encoder
battery voltage is
lower than the
specified value.)
The battery connection is incor-
rect.
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.
(cont’d)
Alarm Number:
Alarm Name
(Alarm Description)
Cause
Investigative Actions
Corrective Actions
