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15.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
15-71
15
Maintenance
Servomotor
Moves with-
out a Refer-
ence Input
A failure occurred in the SER-
VOPACK.
–
Turn OFF the power
supply to the servo
system.
Replace the SERVO-
PACK.
–
The count-up direction of the
linear encoder does not
match the forward direction
of the Moving Coil in the
motor.
Check the directions.
Change the setting of
Pn080 = n.
X
(Motor Phase Selec-
tion).
Match the linear
encoder direction and
Servomotor direction.
Polarity detection was not
performed correctly.
Check to see if electrical
angle 2 (electrical angle
from polarity origin) at any
position is between
±
10
°
.
Correct the settings for
the polarity detection-
related parameters.
–
Dynamic
Brake Does
Not Operate
The setting of Pn001 =
n.
X (Servo OFF or
Alarm Group 1 Stopping
Method) is not suitable.
Check the setting of
Pn001 = n.
X.
Set Pn001 = n.
X
correctly.
–
The dynamic brake resistor is
disconnected.
Check the moment of
inertia, motor speed, and
dynamic brake frequency
of use. If the moment of
inertia, motor speed, or
dynamic brake frequency
of use is excessive, the
dynamic brake resis-
tance may be discon-
nected.
Turn OFF the power
supply to the servo
system.
Replace the SERVO-
PACK. To prevent dis-
connection, reduce the
load.
–
There was a failure in the
dynamic brake drive circuit.
–
There is a defective
component in the
dynamic brake circuit.
Turn OFF the power
supply to the servo
system.
Replace the SERVO-
PACK.
–
Abnormal
Noise from
Servomotor
The Servomotor vibrated
considerably while perform-
ing the tuning-less function
with the default settings.
Check the waveform of
the motor speed.
Reduce the load so
that the moment of
inertia ratio or mass
ratio is within the allow-
able value, or increase
the load level or reduce
the rigidity level in the
tuning-less level set-
tings.
If the situation is not
improved, disable the
tuning-less function
(i.e., set Pn170 to
n.
0) and execute
autotuning either with
or without a host refer-
ence.
Continued on next page.
Continued from previous page.
Problem
Possible Cause
Confirmation
Correction
Reference