Mitsubishi Electric Melservo-J4 Instruction Manual page 133

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.
Home position deviates at home
position return.
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.
For the dog type home position
return, the point which the dog
turns off and the point which Z-
phase pulse is detected (CR input
position) are too close.
The in-position range is too large.
The proximity dog switch is
failure. Or mounting proximity dog
switch is incomplete.
The program on the controller
side is incorrect.
Checkpoint
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.
Check if a fixed amount (in one
revolution) deviates.
Check the setting of the in-
position range in [Pr. PA10].
Check if the proximity dog signal
is inputted correctly.
Check the program on the
controller side such as home
position address settings or
sequence programs.
1 TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
1.6 Trouble which does not trigger alarm/warning
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.
Adjust the dog position.
Set a narrower in-position range.
Repair or replace the proximity
dog switch. Adjust the mounting of
the proximity dog switch.
Review the programs on the
controller side.
Target
[A]
1
[B]
[WB]
[RJ010]
[GF]
[A]
[B]
[WB]
[RJ010]
[GF]
[A]
[A]
[B]
[WB]
[RJ010]
[GF]
[A]
[B]
[WB]
[RJ010]
[GF]
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