Mitsubishi Electric Melservo-J3 Series MR-J3-B, Instruction Manual

Page: 381 / 802

11 - 24
11. TROUBLESHOOTING
Description Check method Possible cause Action
The rotation
accuracy is low.
(The rotation
speed is
instable.) 1. If the servo motor can be driven
safely, repeat acceleration and
deceleration three times or
more to complete auto tuning.
2. Increase the auto tuning
response. (Parameter
No.PA09). (Except for the
manual mode)
1. The servo gain is low.
2. The auto tuning response is low. Increase the auto tuning response, and
readjust the gain. (Refer to chapter 9.)
Check if limiting torque (TLC) is
on .
1. Check with the external I/O
signal display in the diagnostic
mode.
2. Check with "Input/output I/F
Display" command of "Monitor"
menu on MR Configurator.
An unintended torque limit is enabled.
(When the torque limit is enabled,
limiting torque (TLC) is on. ) Cancel the torque limit.
Check if the maximum torque
exceeds the torque limit value.
1. Check the "instantaneous
torque" in the status display.
2. Check the torque ripple with
“Graph” command of "Monitor"
menu on MR Configurator .
The maximum torque is insufficient.
1. Shortage of servo capacity.
2. Too large load.
1. Reduce the load by changing the
mass and shape of the workpiece.
2. Reduce the effective load ratio by
increasing acceleration/deceleration
time.
The setting of the torque limit is
incorrect.
(Set with parameter
No.PA11, PA12, PC35) Review the torque limit setting.
Unsteady
vibration at a
stop. 1. If the servo motor can be driven
safely, repeat acceleration and
deceleration three times or
more to complete auto tuning.
2. Increase auto tuning response
(Parameter No.PA09). (Except
for the manual mode)
1. The servo gain is low.
2. The auto tuning response is low. Increase the auto tuning response, and
readjust the gain. (Refer to chapter 9.)
The servo motor
starts rotating
upon the power-
on of the servo
amplifier/the
servo motor
starts rotating
upon servo-on.
Check if servo-on is on. Servo-on has been on at power-on. Review the controller programs.
For a servo motor with an
electromagnetic brake,
check the timing of releasing the
electromagnetic brake. 1. The sequence of releasing the
electromagnetic brake is incorrect.
2. The power supply for the
electromagnetic brake is
malfunctioning.
1. Review the sequence of releasing
the electromagnetic brake.
2. Check the power supply for the
electromagnetic brake.
Check the servo motor power
cable. The output circuit is in open phase. Review the wiring of the servo motor
power cable.
The position
deviates at the
home position
return. A fixed amount (in one revolution)
deviates. (Dog type home position
return)
Detection of a zero pulse is near dog off
position. (Dog type home position return) Adjust the installation of the proximity
dog switch.
Check the in-position range
(Parameter No.PA10). The in-position range is too large. Set a narrower in-position range.
Check if the proximity dog signal
is inputted correctly. 1. The proximity dog switch is faulty.
2. The installation of the proximity dog is
faulty.
1. Repair or replace the proximity dog
switch.
2. Adjust the installation of the
proximity dog switch.