YASKAWA SGDV-OCA05A

14.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
14-62
Absolute
Encoder
Position
Deviation
Error (The
position
that was
saved in the
host con-
troller when
the power
was turned
OFF is dif-
ferent from
the posi-
tion when
the power
was next
turned ON.)
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.
Turn OFF the power sup-
ply to the servo system.
Check to see if there is
noise interference on the
I/O signal line from the
encoder or Serial Con-
verter Unit.
Implement counter-
measures against noise
for the encoder or
Serial Converter Unit
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 Servomotor
installation (mounting sur-
face 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 power
supply to the servo
system.
Replace the Servomo-
tor or linear encoder.
−
A failure occurred in the SER-
VOPACK.
−
Turn OFF the power
supply to the servo
system.
Replace the SERVO-
PACK.
−
Continued on next page.
Continued from previous page.
Problem Possible Cause Confirmation Correction Reference