YASKAWA E-7-Series SGD7S Product Manual page 478

Problem 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-
Abnormal
nal cable specifications.
Noise from
Servomotor
Noise interference occurred
because an I/O signal cable
is too long.
Noise interference occurred
because of incorrect Encoder
Cable specifications.
Noise interference occurred
because the Encoder Cable
is too long.
Noise interference occurred
because the Encoder Cable
is damaged.
12.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
Confirmation
Check the waveform of
the motor speed.
Check to see if there are
any loose mounting
screws.
Check to see if there is
misalignment in the cou-
pling.
Check to see if the cou-
pling is balanced.
Check for noise and
vibration around the bear-
ings.
Check for any foreign
matter, damage, or defor-
mation in the machine's
moving parts.
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
2
0.12 mm .
Check the lengths of the
I/O signal cables.
Make sure that the rotary
or Linear Encoder Cable
satisfies the specifica-
tions. Use a shielded
twisted-pair wire cable or
a screened twisted-pair
cable with a conductors
of at least 0.12 mm
Check the length of the
Encoder Cable.
Check the Encoder Cable
to see if it is pinched or
the sheath is damaged.
Continued from previous page.
Correction
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.
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.
Use cables that satisfy
the specifications.
2
.
• 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.
Replace the Encoder
Cable and correct the
cable installation envi-
ronment.
Reference
page 8-11
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