Mitsubishi Electric Melservo-J4 Instruction Manual page 131

Description
The speed of the servo motor or
linear servo motor is not
increased. Or the speed is
increased too much.
The servo motor vibrates with low
frequency.
Cause
The setting of the speed
command, speed limit, or
electronic gear is not correct.
The connection of the servo motor
is incorrect.
The voltage of the main circuit
power supply has dropped.
For a servo motor with an
electromagnetic brake, the brake
has not released.
The selection of SP1 (Speed
selection 1), SP2 (Speed
selection 2), or SP3 (Speed
selection 3) is incorrect in the
speed control mode or the torque
control mode.
An analog signal is not input
correctly in the speed control
mode or the torque control mode.
The selection of SPD1 (Speed
selection 1), SPD2 (Speed
selection 2), SPD3 (Speed
selection 3), or SPD4 (Speed
selection 4) is incorrect in the
positioning mode (point table
method) with BCD input.
An analog signal is not input
correctly in the positioning mode
(point table method and program
method).
The selection of OV0 (Digital
override selection 1), OV1 (Digital
override selection 2), OV2 (Digital
override selection 3), or OV3
(Digital override selection 4) is
incorrect in the positioning mode
(indexer method).
The estimated value of the load to
motor inertia ratio by auto tuning
is incorrect. When the load to
motor inertia ratio is set by
manual, the setting value is
incorrect.
The command from the controller
is unstable.
Torque or thrust during
acceleration/deceleration is
overshooting exceeding the limit
of the servo motor when the motor
stops.
The servo gain is low. Or the
response of auto tuning is low.
Checkpoint
Check the settings of the speed
command, speed limit, and
electronic gear.
Check the wiring of U/V/W.
Check if the voltage of the main
circuit power supply dropped.
Check the power supply of the
electromagnetic brake.
Check SP1 (Speed selection 1),
SP2 (Speed selection 2), and SP3
(Speed selection 3), and then
check if the selected internal
speed is correct.
Check the values of the analog
speed command and the analog
torque command using the status
display or MR Configurator2.
Check SPD1 (Speed selection 1),
SPD2 (Speed selection 2), SPD3
(Speed selection 3) and SPD4
(Speed selection 4), and then
check if the selected internal
speed is correct.
Check the value of VC (Analog
override) using the status display
or MR Configurator2.
Check OV0 (Digital override
selection 1), OV1 (Digital override
selection 2), OV2 (Digital override
selection 3) and OV3 (Digital
override selection 4), and then
check if the selected override
level ([%]) is correct.
If the servo motor may be driven
with safety, repeat acceleration
and deceleration several times to
complete auto tuning. Check if the
load to motor inertia ratio is proper
compared with the actual ratio for
manual setting.
Check the command from the
controller.
Check the effective load ratio
during acceleration/deceleration if
torque/thrust exceeds the
maximum torque/thrust.
Check if the trouble is solved by
increasing auto tuning response
([Pr. PA09]).
1 TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
1.6 Trouble which does not trigger alarm/warning
Action
Review the settings of the speed
command, speed limit, and
electronic gear.
Connect it correctly.
Increase the voltage of the main
circuit power supply.
Turn on the electromagnetic brake
power.
Review the settings of SP1
(Speed selection 1), SP2 (Speed
selection 2), SP3 (Speed
selection 3), and setting of internal
speed.
Input the analog signal correctly.
Review the wiring.
Review the settings of SPD1
(Speed selection 1), SPD2 (Speed
selection 2), SPD3 (Speed
selection 3), SPD4 (Speed
selection 4), and setting of internal
speed.
Set the VC (Analog override) and
input the analog signal correctly.
Review the wiring.
Review the settings of OV0
(Digital override selection 1), OV1
(Digital override selection 2), OV2
(Digital override selection 3), and
OV3 (Digital override selection 4).
Execute auto tuning and one-
touch tuning to reset the load to
motor inertia ratio. Set the load to
motor inertia ratio correctly for
manual setting.
Review the command from the
controller.
Check the cable for command if
there is failure such as
disconnection.
Reduce the effective load ratio by
increasing acceleration/
deceleration time and reducing
load.
Adjust gains.
Target
[A]
1
[B]
[WB]
[RJ010]
[GF]
[A]
[A]
[B]
[WB]
[RJ010]
[GF]
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