Mitsubishi Electric MELSERVO-J3W Series Instruction Manual page 452

15. MR-J3W-0303BN6 SERVO AMPLIFIER
Alarm No.: 31 Name: Overspeed
Alarm content
Display Detail name
31.1 Abnormal motor 1) The command from the
speed
2) The servo motor was
3) The servo system is
4) The velocity waveform has
5) The speed overshot when
6) Encoder failure
The servo motor seed has exceeded the permissible instantaneous speed.
Cause
controller is excessive.
driven with maximum
torque and the speed
overshot.
unstable and oscillating.
overshot.
the voltage was recovered
from a temporary bus
voltage drop during driving.
Stop system: Each axis
Check method
Check if the command The command was
from the controller is over the permissible
over the permissible speed.
speed.
The command was
below the
permissible speed.
Check if the torque at It is the maximum
acceleration is the torque.
maximum torque.
It is lower than the
maximum torque.
Check if the servo It is oscillating.
motor is oscillating.
It is not oscillating.
Check if it is It is overshooting.
overshooting because
the acceleration time
constant is short.
It is not
overshooting.
Check if a temporary The bus voltage
bus voltage drop occurs dropped.
during driving.
Bus voltage did not
drop.
Check if the alarm is It is lower.
occurring when the
actual speed of the
servo motor is
permissible
instantaneous speed or
lower.
15 - 47
Check result
Check operation pattern.
Check 2).
Increase the
acceleration/deceleration
time constant. Or reduce
the load.
Check 3).
Adjust the servo gain with
the auto tuning. Or reduce
the load.
Check the applied voltage
of the main circuit is
48VDC when 24VDC is set
for the main circuit power
supply.
Increase the acceleration
time constant.
Check 4).
Increase the
acceleration/deceleration
time constant.
Check 5).
Check the power supply
capacity of the 24VDC
main circuit power supply.
Increase the voltage of the
24VDC main circuit power
supply within the
permissible range.
Change the voltage of the
main circuit power to
48VDC.
Check operation pattern.
Check 6).
Replace the servo motor.
Action