10.2 Troubleshooting Based on the Operation and Conditions of the Servo Drive
10-21
10
Maintenance
Servomotor
Moves
Instanta-
neously and
Then Stops, or
Operation Is
Not Stable
There is a mistake in the
Servomotor wiring.
Check the wiring.
Wire the Servomotor
correctly.
−
There is a mistake in the
encoder wiring.
Check the wiring.
Wire the encoder cor-
rectly.
−
The model of Servomo-
tor that is being used
does not agree with the
setting of Pn08A (Motor
Selection Switch).
Check the model of Ser-
vomotor that is being
used and the setting of
Pn08A (Motor Selection
Switch).
Make sure that the
model of Servomotor
that is being used agrees
with the setting of Pn08A
(Motor Selection Switch).
There is a faulty connec-
tion in the Servomotor
wiring.
The connector connec-
tions for the power wires
(U, V, and W phases) and
the encoder may be
unstable. Check the wir-
ing.
•
Insert connectors firmly
until the lock mecha-
nisms lock into place.
•
Tighten any loose con-
nectors and correct the
wiring.
−
Servomotor
Moves without
a Reference
Input
A failure occurred in the
SERVOPACK.
−
Replace the SERVO-
PACK.
−
Abnormal
Noise from
Servomotor
The machine mounting is
not secure.
Check to see if there are
any loose mounting
screws.
Tighten the mounting
screws.
−
The machine mounting is
not secure.
Check to see if there is
misalignment in the cou-
pling.
Align the coupling.
−
Check to see if the cou-
pling is balanced.
Balance the coupling.
−
The bearings are defec-
tive.
Check for noise and
vibration around the
bearings.
Replace the Servomotor.
−
There is a vibration
source at the driven
machine.
Check for any foreign
matter, damage, or
deformation in the
machine’s moving parts.
Consult with the machine
manufacturer.
−
The Encoder Cable does
not satisfy specifications.
Check the Encoder
Cable to see if it satisfies
specifications.
Use cables that satisfy
the specifications.
−
There is excessive exter-
nal noise interference on
the Encoder Cable.
Check to see if the
Encoder Cable is bun-
dled with a high-current
line or installed near a
high-current line. Check
to see if there is noise
interference on the signal
line from the encoder.
Correct the cable layout
so that no surge is
applied by high-current
lines. Take measures to
prevent noise interfer-
ence from the signal lines
on the encoder cable.
−
There is variation in the
FG potential because of
the influence of
machines on the Servo-
motor side, such as a
welder.
Check to see if the
machines are correctly
grounded.
Properly ground the
machines to separate
them from the FG of the
encoder.
−
The encoder was sub-
jected to excessive
vibration or shock.
Check to see if vibration
from the machine
occurred. Check the Ser-
vomotor installation
(mounting surface preci-
sion, securing state, and
alignment).
Reduce machine vibra-
tion. Improve the mount-
ing conditions of the
Servomotor.
−
A failure occurred in the
encoder.
−
Replace the Servomotor.
−
Continued on next page.
Continued from previous page.
Problem
Possible Cause
Confirmation
Correction
Reference
