8-17
8-3 Troubleshooting
Troubleshooting
8
The Servomotor
rotates
without a
command.
There is a small input for
speed command mode.
Check that there is no input
for speed command mode.
Set the speed command to
0, or switch to position con-
trol mode.
There is a small input for
torque command mode.
Check that there is no input for
torque command mode.
Switch from torque control
mode to position control
mode.
The Servomotor
rotates in the
direction opposite
to the command.
The Operating Direction
Setting (Pn043) setting is
incorrect.
Check the Operating Direction
Setting (Pn043) value.
Change the Operating
Direction Setting (Pn043)
value.
NCF71 command is
incorrect.
Set values are inappropriate for
an absolute command.
The polarity is incorrect for an
incremental command.
Check the current and
target values.
Check the rotation
direction.
The holding
brake does not
work.
Power is supplied to the
holding brake.
Check whether power is supplied to
the holding brake.
Check the brake interlock
(BKIR) signal and the relay
circuit.
Check that the holding
brake is not worn down.
The Servomotor
is overheating.
The load is too large.
Measure the torque using the front
panel IM or a tool.
Slow down the
acceleration/deceleration.
Lower the speed and
measure the load.
The heat radiation condi-
tions for the Servomotor
have worsened.
Check that the specified heat
radiation conditions are satisfied.
For a Servomotor with a brake,
check the load ratio.
Improve the heat radiation
conditions.
Reduce the load.
Improve ventilation.
The ambient temperature is
too high.
Check that the ambient tempera-
ture has not exceeded 40
°
C.
Radiate heat and cool.
Reduce the load ratio.
The Servomotor
rotation is
unstable.
Load and gain do not
match.
Check the response waveforms for
speed and torque.
Adjust the speed loop gain
so that the rotation is
stabilized.
Load inertia exceeds the
specified range.
Calculate the load inertia.
Check if the adjustments
can be made via manual
tuning.
Increase the capacity of the
Servomotor.
Low rigidity is resulting in
vibration.
Measure the vibration frequency of
the load.
Enable damping control, and
set the vibration filter fre-
quencies.
Loose coupling with the
machine, and/or large
gaps.
Check coupling with the machine.
Tighten the coupling with the
machine.
Symptom
Probable cause
Items to check
Countermeasure