YASKAWA SGD7S-****20A Series Product Manual page 481

12.5 Troubleshooting Based on the Operation and Conditions of the Servomotor
Problem
Abnormal
Noise from
Servomotor
12-62
Possible Cause
The Servomotor vibrated
considerably while perform-
ing the tuning-less function
with the default settings.
The machine mounting is not
secure.
The machine mounting is not
secure.
The bearings are defective.
There is a vibration source at
the driven machine.
Noise interference occurred
because of incorrect I/O sig-
nal cable specifications.
Noise interference occurred
because an I/O signal cable
is too long.
Confirmation
Check the waveform of
the motor speed.
Turn OFF the power sup-
ply to the servo system.
Check to see if there are
any loose mounting
screws.
Turn OFF the power sup-
ply to the servo system.
Check to see if there is
misalignment in the cou-
pling.
Turn OFF the power sup-
ply to the servo system.
Check to see if the cou-
pling is balanced.
Turn OFF the power sup-
ply to the servo system.
Check for noise and
vibration around the bear-
ings.
Turn OFF the power sup-
ply to the servo system.
Check for any foreign
matter, damage, or defor-
mation in the machine's
moving parts.
Turn OFF the power sup-
ply to the servo system.
Check the I/O signal
cables to see if they sat-
isfy specifications. Use
shielded twisted-pair
cables or screened
twisted-pair cables with
conductors of at least
2
0.12 mm (stranded wire).
Turn OFF the power sup-
ply to the servo system.
Check the lengths of the
I/O signal cables.
Continued from previous page.
Correction Reference
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.
page 8-12
If the situation is not
improved, disable the
tuning-less function
(i.e., set Pn170 to
n.0) and execute
autotuning either with
or without a host refer-
ence.
Tighten the mounting
–
screws.
Align the coupling.
–
Balance the coupling.
–
Replace the Servomo-
–
tor.
Consult with the
–
machine manufacturer.
Use cables that satisfy
–
the specifications.
The I/O signal cables
must be no longer than
–
3 m.
Continued on next page.