YASKAWA SGD7S - Page 525

12.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
12-56
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.
page 8-12
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 defective.
Check for noise and
vibration around the bear-
ings.
Replace the Servomo-
tor.
–
There is a vibration source at
the driven machine.
Check for any foreign
matter, damage, or defor-
mation in the machine’s
moving parts.
Consult with the
machine manufacturer.
–
Noise interference occurred
because of incorrect I/O sig-
nal cable specifications.
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
0.12 mm
2
(stranded wire).
Use cables that satisfy
the specifications.
–
Noise interference occurred
because an I/O signal cable
is too long.
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.
Check the Encoder Cable
to see if it satisfies speci-
fications. Use shielded
twisted-pair cables or
screened twisted-pair
cables with conductors of
at least 0.12 mm
2
(stranded wire).
Use cables that satisfy
the specifications.
–
Noise interference occurred
because the Encoder Cable
is too long.
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.
–
Noise interference occurred
because the Encoder Cable
is damaged.
Check the Encoder Cable
to see if it is pinched or
the sheath is damaged.
Replace the Encoder
Cable and correct the
cable installation envi-
ronment.
–
Continued on next page.
Continued from previous page.
Problem Possible Cause Confirmation Correction Reference