YASKAWA E-7S SERVOPACK SGD7S - Page 584

15.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
15-73
15
Maintenance
Abnormal
Noise from
Servomotor
Noise interference occurred
because the Encoder Cable
is too long.
Turn OFF the power sup-
ply to the servo system.
Check the length of the
Encoder Cable.
• Rotary Servomotors:
The Encoder Cable
length must be 50 m
max.
• Linear Servomotors:
Make sure that the
Serial Converter Unit
cable is no longer
than 20 m and that
the Linear Encoder
Cable and the Sensor
Cable are no longer
than 15 m each.
–
Noise interference occurred
because the Encoder Cable
is damaged.
Turn OFF the power sup-
ply to the servo system.
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 power sup-
ply to the servo system.
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 power sup-
ply to the servo system.
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 power
supply to the servo
system.
Implement counter-
measures against noise
for the encoder wiring.
–
The encoder was subjected
to excessive vibration or
shock.
Turn OFF the power sup-
ply to the servo system.
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.
–
Turn OFF the power
supply to the servo
system.
Replace the Servomo-
tor.
–
A failure occurred in the
Serial Converter Unit.
–
Turn OFF the power
supply to the servo
system.
R
eplace the Serial Con-
verter Unit.
–
A failure occurred in the linear
encoder.
–
Turn OFF the power
supply to the servo
system.
Replace the linear
encoder.
–
Continued on next page.
Continued from previous page.
Problem Possible Cause Confirmation Correction Reference