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

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11. TROUBLESHOOTING
Description Check method Possible cause Action
The servo motor
vibrates. 1. If the servo motor can be driven
safely, repeat acceleration and
deceleration three times or
more to complete auto tuning.
2. Reduce the auto tuning
response (parameter
No.PA09).
(Except for the manual mode)
1. The servo gain is too high.
2. The auto tuning response is too high. Reduce the auto tuning response, and
readjust the gain. (Refer to chapter 9).
If the servo motor can be driven
safely, execute the adaptive
tuning. The machine is vibrating (resonating). Adjust the machine resonance
suppression filter. (Refer to section
10.3.)
If the servo motor can be driven
safely, execute tuning with the
advanced gain search on MR
Configurator, MRZJW3-SETUP
221E (C2 or later).
The machine is vibrating (resonating). Adjust gains. (Refer to chapter 9.)
If the servo motor can be driven
safely, execute tuning with the
advanced vibration suppression
control. The load side is vibrating. Execute the filter adjustment.
(Refer to section 10.4.)
Display the cumulative feedback
pulses in "high speed monitor"
command of "monitor" menu on
MR Configurator, and check if its
numerical value is skipping. Feedback pulses are being miscounted
due to superimposed noise in the
encoder cable. Take countermeasures against noise
by laying the encoder cable apart from
power cables, etc.
Check if there is a backlash on
the machine part. There is a backlash between the servo
motor and the machine (such as a gear
and coupling). Adjust the backlash on the coupling
and the machine part.
Check the mounting part of the
servo motor. The rigidity of the servo motor mounting
part is low. Increase the rigidity of the mounting
part by methods, such as increasing
the board thickness and reinforcing the
part with ribs.
Check the servo motor power
cable. The output circuit is in open phase. Review the wiring of servo motor
power cable.
Check if the vibration varies
according to the speed. An unbalanced torque on machine side
is large. Adjust the balance of the machine
side.
Check the mounting accuracy of
the servo motor and machine. The eccentricity due to a core gap is
large. Review the direct accuracy.
Check the load for the shaft of the
servo motor. The load for the shaft of the servo motor
is large. Adjust the load for the shaft to within
the specifications of the servo motor.
For the shaft permissible load, refer to
Servo Motor Instruction Manual
(Vol.2).
Check the vibration from outside. An external vibration propagated to the
servo motor.
Prevent the vibration from the external
vibration source.