Mitsubishi Electric MELSERVO-J4 Instruction Manual page 128

1. TROUBLESHOOTING FOR SERVO AMPLIFIER (DRIVE UNIT)
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.
Possible cause
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.
Check result
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 - 121
Action
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]
[A]
[B]
[WB]
[RJ010]
[GF]