15.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
15-54
Abnormal
Noise from
Servomotor
The Servomotor vibrated
considerably while perform-
ing the tuning-less function
with the default settings.
Check the waveform of
the motor speed.
Reduce the load so
that the moment of
inertia ratio or mass
ratio is within the allow-
able value, or increase
the load level or reduce
the rigidity level in the
tuning-less level set-
tings.
The machine mounting is not
secure.
Turn OFF the Servo Sys-
tem. Check to see if there
are any loose mounting
screws.
Tighten the mounting
screws.
–
The machine mounting is not
secure.
Turn OFF the Servo Sys-
tem. Check to see if there
is misalignment in the
coupling.
Align the coupling.
–
Turn OFF the Servo Sys-
tem. Check to see if the
coupling is balanced.
Balance the coupling.
–
The bearings are defective.
Turn OFF the Servo Sys-
tem. Check for noise and
vibration around the bear-
ings.
Replace the Servomo-
tor.
–
There is a vibration source at
the driven machine.
Turn OFF the Servo Sys-
tem. Check for any for-
eign matter, damage, or
deformation in the
machine’s moving parts.
Consult with the
machine manufacturer.
–
Noise interference occurred
because of incorrect I/O Sig-
nal Cable specifications.
Turn OFF the Servo Sys-
tem. Check the I/O Signal
Cables to see if they sat-
isfy specifications. Use
shielded twisted-pair wire
cables or screened
twisted-pair cables with
conductors of at least
0.12 mm
2
.
Use cables that satisfy
the specifications.
–
Noise interference occurred
because an I/O Signal Cable
is too long.
Turn OFF the Servo Sys-
tem. Check the lengths of
the I/O Signal Cables.
The I/O Signal Cables
must be no longer than
3 m.
–
Noise interference occurred
because of incorrect Encoder
Cable specifications.
Turn OFF the Servo Sys-
tem. Make sure that the
rotary or Linear Encoder
Cable satisfies the speci-
fications. Use a shielded
twisted-pair wire cable or
a screened twisted-pair
cable with a conductors
of at least 0.12 mm
2
.
Use cables that satisfy
the specifications.
–
Noise interference occurred
because the Encoder Cable
is too long.
Turn OFF the Servo Sys-
tem. Check the length of
the Encoder Cable.
•
Rotary Servomotors:
The Encoder Cable
length must be 50 m
max.
•
Linear Servomotors:
Make sure that the
Serial Converter Unit
Cable is no longer
than 20 m and that
the Linear Encoder
Cable and the Sensor
Cable are no longer
than 15 m each.
–
Continued on next page.
Continued from previous page.
Problem
Possible Cause
Confirmation
Correction
Reference
