Yaskawa Sigma II Series SGMVH User Manual
Page 300

10.1 Troubleshooting
10-19
10
Inspection, Maintenance, and
T
roubleshooting
Overtravel
(OT)
(Movement
over the zone
specified by
the host con-
troller)
(cont’d)
Excessive vibration and shock to the
encoder
Machine vibration occurred or servomotor
mounting such as mounting surface preci-
sion, fixing, alignment is incorrect.
Reduce the machine vibration or mount the servomotor
securely.
Encoder fault
−
Replace the servomotor.
SERVOPACK fault
A SERVOPACK fault occurred.
Replace the SERVOPACK.
Position error
(without
alarm)
Unsecured coupling between
machine and servomotor
Check if a position error occurs at the cou-
pling between machine and servomotor.
Secure the coupling between the machine and servomo-
tor.
Noise interference due to improper
input signal cable specifications
Check if the cable meets the recommended
specifications.
Use input signal cable with the specified specifications.
Noise interference because the input
signal cable distance is too long.
The wiring distance must be 3 m max. and
the impedance several hundreds ohm max.
The input signal cable distance must be within the speci-
fied range.
Encoder fault (pulse count does not
change)
−
Replace the servomotor.
Servomotor
Overheated
Surrounding air temperature too high
Measure servomotor surrounding air tem-
perature.
Reduce surrounding air temperature to 40
°C max.
Servomotor surface dirty
Check visually.
Clean dust and oil from servomotor surface.
Overloaded
Run under no load.
Reconsider load and operation conditions or replace with
larger capacity servomotor.
Table 10.7 Troubleshooting for Malfunction without Alarm Display (cont’d)
Symptom
Cause
Inspection
Corrective Actions
: Turn OFF the servo system before executing operations.