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

Page: 750 / 802

17 - 65
17. SPEED CONTROL OPERATION
Description Check method Possible cause Action
The speed of the
servo motor is
not increased.
Or the speed is
increased too
much.
Check the settings of the speed
command and electronic gear.
The setting of the speed command and
electronic gear are incorrect. Review the settings of the speed
command and electronic gear.
Check the servo motor power
cable. The output circuit is open phase. Review the wiring of the servo motor
power cable.
Check if the voltage of the main
circuit power supply dropped. The voltage of the main circuit power
supply has dropped.
1. Set the main circuit power supply
within the permissible voltage
fluctuation range of specifications.
2. Check the wiring of the main circuit
power supply.
For a servo motor with an
electromagnetic brake, check
the power supply of the
electromagnetic brake. The electromagnetic brake has not
been released. Turn on the power supply of the
electromagnetic brake to release the
brake.
The servo motor
vibrates with low
frequency. If the servo motor can be driven
safely, repeat acceleration and
deceleration three or four times
to complete auto tuning. Failed to estimate the load to motor
inertia ratio by auto tuning.
If the auto tuning mode 2 or the manual
mode is being used, the setting of load
to motor inertia ratio (parameter
No.PB06) is incorrect.
Adjust gains. (Refer to chapter 9.)
If the auto tuning mode 2 or the
manual mode is being used, review
the setting of load to motor inertia ratio
(parameter No.PB06).
Check the command from the
controller. The command from the controller is
unstable.
1. Review the command from the
controller.
2. Check if the cable for a command
has any failure, such as a
disconnection.
Check if the mechanical part is
malfunctioning.
(Example)
1. If the timing belt is loose.
2. If it has abrasion. Load of the mechanical part has
changed.
1. Readjust the gain.
(Refer to chapter 9.)
2. Maintain the mechanical part.
Check if the required torque of
the machine exceeds the
maximum torque of the servo
motor. Torque during
acceleration/deceleration is
overshooting exceeding the limit of the
servo motor when the motor stops.
Reduce the load by increasing the
acceleration and deceleration time or
reducing the mass of the workpiece.
Increase the auto tuning
response (parameter No.PA09).
(Other than 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.)