Mitsubishi Electric MELSERVO-J4 Instruction Manual Trouble Shooting page 32

1. TROUBLESHOOTING
Alarm No.: 31 Name: Overspeed
Alarm content
Detail
Detail name
No.
31.1 Abnormal motor (1) The command pulse
speed
(2)
(3) The command from the
(4) A larger speed
(5)
(6)
(7) The velocity waveform
(8)
(9) The encoder or liner
The servo motor seed has exceeded the permissible instantaneous speed.
The linear servo motor seed has exceeded the permissible instantaneous speed.
Cause
Check the command
frequency is high. pulse frequency.
The settings of the Check the setting
electronic gear are value of the electronic
incorrect. gear.
Check if the command
controller is excessive. from the controller is
over the permissible
speed.
Check that the actual
command than the motor speed is higher
overspeed alarm level than the setting value
was inputted. of [Pr. PC08
Overspeed alarm
detection level].
The servo motor was at Check if the torque
the maximum torque (thrust) at the time of
(maximum thrust) at the acceleration is the
time of acceleration. maximum torque
(maximum thrust).
The servo system is Check if the servo
unstable and oscillating. motor is oscillating.
Check if it is
has overshot. overshooting because
the acceleration time
constant is too short.
The connection Check the connection
destination of the destinations of CN2A,
encoder cable is CN2B, and CN2C.
incorrect.
Check if the alarm is
encoder is occurring during less
malfunctioning. than permissible
instantaneous speed.
Check method Check result
The command pulse
frequency is high.
The command pulse
frequency is low.
The setting value is
incorrect.
The setting value is
correct.
It is over the
permissible speed.
It is less than the
permissible speed.
The motor speed is
higher than the
overspeed alarm
detection level.
The motor speed is
lower than the
overspeed alarm
level.
It is the maximum
torque (maximum
thrust).
It is less than the
maximum torque
(maximum thrust).
It is oscillating.
It is not oscillating.
It is overshooting.
It is not overshooting. Check (8).
It is not correct.
It is correct.
It is occurring during
less than permissible
instantaneous speed.
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Action Target
Check operation [A]
pattern.
Check (2).
Review the settings.
Check (5).
Check operation [B]
pattern. [WB]
[RJ010]
Check (4).
Review the [Pr. PC08]
setting.
Check (5).
Increase the [A]
acceleration/decelerat [B]
ion time constant. Or [WB]
reduce the load. [RJ010]
Check (6).
Adjust the servo gain.
Or reduce the load.
Check (7).
Increase the
acceleration/decelerat
ion time constant.
Wire it correctly. [WB]
Check (9).
Replace the servo [A]
motor or linear [B]
encoder. [WB]
[RJ010]