Mitsubishi Electric MELSERVO-J4 Instruction Manual page 130

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
Description
The rotation accuracy is low.
(The speed is unstable.)
The machine vibrates
unsteadily when it stops.
The servo motor starts to
drive immediately after
power on of the servo
amplifier.
The servo motor starts to
drive immediately after
servo-on.
Possible 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
has been enabled.
The setting of the torque limit
is incorrect.
For a servo motor with an
electromagnetic brake, the
brake has not released.
The command from the
controller is unstable.
The servo gain is low. Or the
response of auto tuning is
low.
SON (Servo-on) is on at
power on.
An analog signal is inputted
from the beginning.
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.
Check result
Check if the trouble is solved
by increasing auto tuning
response ([Pr. PA09]).
Check instantaneous torque
using status display (only [A])
or MR Configurator2 if the
load exceeds the maximum
torque or torque limit value.
Check if TLC (Limiting
torque) is on using status
display or MR Configurator2.
Check if the limiting torque is
too low.
[A]: [Pr. PA11] and [Pr.
PA12], or analog input
[B] [WB] [RJ010]: Setting on
controller side
[GF]: [Pr. PA11], [Pr. PA12],
or setting on controller side
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 auto tuning
response ([Pr. PA09]).
Check if SON (Servo-on) and
RD (Ready) are on using
status display or MR
Configurator2.
Check the status of analog
speed command and analog
torque command using
status display or MR
Configurator2.
Check if the servo motor
drives while 0 V is inputted to
the analog signal.
Check the brake release
timing.
Check the wiring of U/V/W.
1 - 123
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 the
cable for command if there is
failure such as
disconnection.
Adjust gains.
Review the sequence of
SON (Servo-on).
Review the timing of
inputting analog signals.
Execute the VC automatic
offset or adjust offset of the
analog signal with [Pr. PC37]
or [Pr. PC38].
Review the brake release
timing.
Connect it correctly.
Target
[A]
[B]
[WB]
[RJ010]
[GF]
[A]
[B]
[WB]
[RJ010]
[GF]
[A]
[A]
[B]
[WB]
[RJ010]
[GF]