11 Inspection, Maintenance, and Troubleshooting
11.2.3 Troubleshooting of the Servo Drive Alarms
11-22
A.790:
Motor Overheated
(The motor temperature
has exceeded the upper
limit.)
The ambient temperature around
the motor is high.
Check the ambient temperature
around the motor.
Make sure the ambient temperature
around the motor does not increase.
Acceleration and deceleration
were repeated frequently.
−
Make the acceleration/deceleration
of the motor smoother, or change
the operation pattern.
A.791:
Motor Temperature
Detection Error
(The motor thermistor is
either disconnected or is
damaged.)
The cable between the SERVO-
PACK and spindle motor is either
disconnected or has a contact
fault.
Make sure the wiring is not discon-
nected and no contact fault exists.
Correct the wiring.
The thermistor wiring in the spin-
dle motor is disconnected.
−
The spindle motor may be faulty.
Replace the spindle motor.
The thermistor has failed.
−
The spindle motor may be faulty.
Replace the spindle motor.
A.7A0:
Heat Sink in
SERVOPACK
Overheated
(The temperature of the
heat sink in the SERVO-
PACK exceeded 100
°
C,
or the thermistor in the
SERVOPACK was dis-
connected or damaged.)
The operating ambient tempera-
ture is too high.
Check the ambient temperature
using a thermometer.
Improve the installation conditions
of the SERVOPACK and reduce the
operating ambient temperature.
The overload alarm has been
reset by turning OFF the power
too many times.
Check the alarm history to see if the
overload alarm of the SERVO-
PACK was reported.
Change the method for resetting the
alarm.
The installation orientation of the
SERVOPACK is incorrect or the
distance from other equipment is
insufficient.
Check the installation conditions of
the SERVOPACK.
Install the SERVOPACK correctly
as specified.
SERVOPACK failure
−
The SERVOPACK may be faulty.
Replace the SERVOPACK.
The heat sink cooling fan in the
ventilation duct stopped or the
fan in the base mounting unit
stopped.
Make sure that there is no foreign
matter in the fans.
Remove the foreign matter. Or
replace the fan.
A.7AB:
Built-in Fan in
SERVOPACK
Stopped
The fan inside the SERVOPACK
stopped.
Check for foreign matter or debris
inside the SERVOPACK.
Remove the foreign matter. If the
alarm still occurs, the SERVO-
PACK may be faulty. Replace the
SERVOPACK.
A.7AC:
Built-in Fan in
Converter Stopped
(The fan inside the
power regeneration con-
verter stopped.)
The fan inside the power regener-
ation converter stopped.
Check for foreign matter or debris
inside the power regeneration con-
verter.
Remove the foreign matter. If the
alarm still occurs, the power regen-
eration converter may be faulty.
Replace the power regeneration
converter.
(cont’d)
Alarm:
Alarm Name
Cause
Investigative Actions
Corrective Actions
