Mitsubishi Electric MELSERVO-JE Instruction Manual page 71

1. SERVO AMPLIFIER TROUBLESHOOTING
Description
The rotation accuracy is low.
(The rotation speed is
unstable.)
The machine vibrates
unsteadily when it stops.
The servo motor starts
rotating upon the power-on of
the servo amplifier.
The servo motor starts
rotating upon servo-on.
Cause
The servo gain is low. Or the
response of auto tuning is
low.
The torque is insufficient due
to large load.
An unintended torque limit is
enabled.
The setting of the torque limit
is incorrect.
For a servo motor with an
electromagnetic brake, the
brake has not been released.
The command from the
controller is unstable.
The servo gain is low. Or the
response of auto tuning is
low.
SON (Servo-on) has been on
at power-on.
An analog signal has been
inputted from the beginning.
The zero point of an analog
signal deviates.
For a servo motor with an
electromagnetic brake, the
brake release timing is not
correct.
The connection of the servo
motor is incorrect.
Checkpoint
Check if the trouble is solved
by increasing the auto tuning
response ([Pr. PA09]).
Check instantaneous torque
using the status display (only
[A]) or MR Configurator2,
and check if the load
exceeds the maximum
torque or torque limit value.
Check if TLC (Limiting
torque) is on using the status
display or MR Configurator2.
Check if the torque limit
value is too low.
[A]: [Pr. PA11] and [Pr.
PA12], or analog input
[B]: Setting on the controller
side
[C]: [Pr. PA11] and [Pr.
PA12], or analog input
Check the power supply of
the electromagnetic brake.
Check the ripple of the
command frequency with MR
Configurator2.
Check if the trouble is solved
by increasing the auto tuning
response ([Pr. PA09]).
Check if SON (Servo-on) and
RD (Ready) are on using the
status display or MR
Configurator2.
Check the status of the
analog speed command or
the analog torque command
using the status display or
MR Configurator2.
Check if the servo motor
rotates while 0 V is inputted
to the analog signal.
Check the brake release
timing.
Check the wiring of U/V/W.
1 - 64
Action
Adjust gains.
Reduce the load or use a
larger capacity servo motor.
Cancel the torque limit.
Set it correctly.
Turn on the electromagnetic
brake power.
Review the command from
the controller. Check if the
cable for a command has
any failure, such as a
disconnection.
Adjust gains.
Review the sequence of
SON (Servo-on).
Review the timing of
inputting analog signals.
Execute the VC automatic
offset or adjust the offset of
the analog signal with [Pr.
PC37] or [Pr. PC38].
Review the brake release
timing.
Connect it correctly.
Target
[A]
[B]
[C]
[A]
[B]
[C]
[A]
[C]
[A]
[B]
[C]