YASKAWA E-7-Series SGD7S - Page 479

12.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
12-56
Abnormal
Noise from
Servomotor
The Encoder Cable was sub-
jected to excessive noise
interference.
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.
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.
Implement counter-
measures against noise
for the encoder wiring.
–
The encoder was subjected
to excessive vibration or
shock.
Check to see if vibration
from the machine
occurred. Check the Ser-
vomotor installation
(mounting surface preci-
sion, 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.
–
Replace the Servomo-
tor.
–
A failure occurred in the
Serial Converter Unit.
–
Replace the Serial Con-
verter Unit.
–
A failure occurred in the linear
encoder.
–
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.
page 8-23
The setting of Pn100 (Speed
Loop Gain) is too high.
Check the setting of
Pn100.
The default setting is Kv =
40.0 Hz.
Set Pn100 to an appro-
priate value.
–
The setting of Pn102 (Posi-
tion Loop Gain) is too high.
Check the setting of
Pn102.
The default setting is Kp
= 40.0/s.
Set Pn102 to an appro-
priate value.
–
The setting of Pn101 (Speed
Loop Integral Time Con-
stant) is not appropriate.
Check the setting of
Pn101.
The default setting is Ti =
20.0 ms.
Set Pn101 to an appro-
priate value.
–
The setting of Pn103
(Moment of Inertia Ratio or
Mass Ratio) is not appropri-
ate.
Check the setting of
Pn103.
Set Pn103 to an appro-
priate value.
–
Continued from previous page.
Problem Possible Cause Confirmation Correction Reference