YASKAWA E-7S SERVOPACK SGD7S Product Manual page 589

15.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
Problem
Position
Deviation
(without
Alarm)
Servomotor
Overheated
15-78
Possible Cause
The encoder was subjected
to excessive vibration or
shock.
The coupling between the
machine and Servomotor is
not suitable.
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.
There is an overload on the
Servomotor.
Polarity detection was not
performed correctly.
Confirmation
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).
Turn OFF the power sup-
ply to the servo system.
Check to see if position
offset occurs at the cou-
pling between machine
and Servomotor.
Turn OFF the power sup-
ply to the servo system.
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 power sup-
ply to the servo system.
Check the lengths of the
I/O signal cables.
–
–
Measure the surrounding
air temperature around
the Servomotor.
Turn OFF the power sup-
ply to the servo system.
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 power
supply to the servo
system. –
Replace the Servomo-
tor or linear encoder.
Turn OFF the power
supply to the servo
system. –
Replace the SERVO-
PACK.
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.