YASKAWA Sigma-7 Series Product Manual page 137

Problem Possible Cause
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.
Abnormal
Noise from
Noise interference occurred
Servomotor
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.
6.3 Troubleshooting Based on the Operation and Conditions of the Servomotor
Confirmation
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.
Turn OFF the power sup-
ply to the servo system.
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
(stranded wire).
Turn OFF the power sup-
ply to the servo system.
Check the length of the
Encoder Cable.
Turn OFF the power sup-
ply to the servo system.
Check the Encoder Cable
to see if it is pinched or
the sheath is damaged.
Continued from previous page.
Correction
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.
Continued on next page.
Reference
–
–
–
–
–
–
–
–
–
6
6-49