16.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
16-59
16
Maintenance
Abnormal
Noise from
Servomotor
Noise interference occurred
because the Encoder Cable
is damaged.
Turn OFF the Servo Sys-
tem. Check the Encoder
Cable to see if it is
pinched or the sheath is
damaged.
Replace the Encoder
Cable and correct the
cable installation envi-
ronment.
–
The Encoder Cable was sub-
jected to excessive noise
interference.
Turn OFF the Servo Sys-
tem. Check to see if the
Encoder Cable is bundled
with a high-current line or
installed near a high-cur-
rent line.
Correct the cable lay-
out so that no surge is
applied by high-current
lines.
–
There is variation in the FG
potential because of the
influence of machines on the
Servomotor side, such as a
welder.
Turn OFF the Servo Sys-
tem. Check to see if the
machines are correctly
grounded.
Properly ground the
machines to separate
them from the FG of
the encoder.
–
There is a SERVOPACK
pulse counting error due to
noise.
Check to see if there is
noise interference on the
signal line from the
encoder.
Turn OFF the Servo
System. Implement
countermeasures
against noise for the
encoder wiring.
–
The encoder was subjected
to excessive vibration or
shock.
Turn OFF the Servo Sys-
tem. Check to see if
vibration from the
machine occurred. Check
the Servomotor installa-
tion (mounting surface
precision, securing state,
and alignment).
Check the linear encoder
installation (mounting sur-
face precision and secur-
ing method).
Reduce machine vibra-
tion. Improve the
mounting state of the
Servomotor or linear
encoder.
–
A failure occurred in the
encoder.
–
Turn OFF the Servo
System. Replace the
Servomotor.
–
A failure occurred in the
Serial Converter Unit.
–
Turn OFF the Servo
System. Replace the
Serial Converter Unit.
–
A failure occurred in the linear
encoder.
–
Turn OFF the Servo
System. Replace the
linear encoder.
–
Servomotor
Vibrates at
Frequency
of Approx.
200 to 400
Hz.
The servo gains are not bal-
anced.
Check to see if the servo
gains have been cor-
rectly tuned.
Perform autotuning
without a host refer-
ence.
The setting of Pn100 (2100h)
(Speed Loop Gain) is too
high.
Check the setting of
Pn100 (2100h).
The default setting is Kv =
40.0 Hz.
Set Pn100 (2100h) to
an appropriate value.
–
The setting of Pn102 (2102h)
(Position Loop Gain) is too
high.
Check the setting of
Pn102 (2102h).
The default setting is Kp
= 40.0/s.
Set Pn102 (2102h) to
an appropriate value.
–
The setting of Pn101 (2101h)
(Speed Loop Integral Time
Constant) is not appropriate.
Check the setting of
Pn101 (2101h).
The default setting is Ti =
20.0 ms.
Set Pn101 (2101h) to
an appropriate value.
–
The setting of Pn103 (2103h)
(Moment of Inertia Ratio or
Mass Ratio) is not appropri-
ate.
Check the setting of
Pn103 (2103h).
Set Pn103 (2103h) to
an appropriate value.
–
Continued on next page.
Continued from previous page.
Problem
Possible Cause
Confirmation
Correction
Reference