YASKAWA SGD7S-1R9D Product Manual page 541

Problem Possible Cause
The encoder was subjected
to excessive vibration or
shock.
The coupling between the
machine and Servomotor is
not suitable.
Position
Deviation
(without
Alarm)
Noise interference occurred
because of incorrect I/O Sig-
nal Cable specifications.
Noise interference occurred
because an I/O Signal Cable
is too long.
An encoder fault occurred.
(The pulse count does not
change.)
A failure occurred in the SER-
VOPACK.
The surrounding air tempera-
ture is too high.
The surface of the Servomo-
tor is dirty.
Servomotor
Overheated
There is an overload on the
Servomotor.
Polarity detection was not
performed correctly.
15.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
Confirmation
Turn OFF the Servo Sys-
tem. 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).
Turn OFF the Servo Sys-
tem. Check to see if posi-
tion offset occurs at the
coupling between
machine and Servomotor.
Turn OFF the Servo Sys-
tem. Check the I/O Signal
Cables to see if they sat-
isfy specifications. Use a
shielded twisted-pair wire
cable or a screened
twisted-pair cable with
conductors of at least
2
0.12 mm .
Turn OFF the Servo Sys-
tem. Check the lengths of
the I/O Signal Cables.
–
–
Measure the surrounding
air temperature around
the Servomotor.
Turn OFF the Servo Sys-
tem. Visually check the
surface for dirt.
Check the load status
with a monitor.
Check to see if electrical
angle 2 (electrical angle
from polarity origin) at any
position is between ±10°.
Continued from previous page.
Correction Reference
Reduce machine vibra-
tion. Improve the
mounting state of the –
Servomotor or linear
encoder.
Correctly secure the
coupling between the
–
machine and Servomo-
tor.
Use cables that satisfy
–
the specifications.
The I/O Signal Cables
must be no longer than
–
3 m.
Turn OFF the Servo
System. Replace the
–
Servomotor or linear
encoder.
Turn OFF the Servo
System. Replace the
–
SERVOPACK.
Reduce the surround-
ing air temperature to
–
40°C or less.
Clean dirt, dust, and oil
–
from the surface.
If the Servomotor is
overloaded, reduce the
load or replace the
Servo Drive with a
–
SERVOPACK and Ser-
vomotor with larger
capacities.
Correct the settings for
the polarity detection-
–
related parameters.
15
15-61