YASKAWA Sigma-7-Series Product Manual page 125

Problem Possible Cause
The Servomotor
vibrated considerably
while performing the
tuning-less function
with the default set-
tings.
The machine mounting
is not secure.
The machine mounting
is not secure.
The bearings are
defective.
There is a vibration
Abnormal
source at the driven
Noise from machine.
Servomotor
Noise interference
occurred because of
incorrect I/O signal
cable specifications.
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.
5.7 Troubleshooting Based on the Operation and Conditions of the Servomotor
Confirmation
Check the waveform of the
motor speed.
Turn OFF the power supply
to the servo system.
Check to see if there are any
loose mounting screws.
Turn OFF the power supply
to the servo system.
Check to see if there is mis-
alignment in the coupling.
Turn OFF the power supply
to the servo system.
Check to see if the coupling
is balanced.
Turn OFF the power supply
to the servo system.
Check for noise and vibra-
tion around the bearings.
Turn OFF the power supply
to the servo system.
Check for any foreign mat-
ter, damage, or deformation
in the machine's moving
parts.
Turn OFF the power supply
to the servo system.
Check the I/O signal cables
to see if they satisfy specifi-
cations. Use shielded
twisted-pair wire cables or
screened twisted-pair
cables with conductors of at
2
least 0.12 mm .
Turn OFF the power supply
to the servo system.
Check the lengths of the I/O
signal cables.
Turn OFF the power supply
to the servo system.
Make sure that the rotary
Encoder Cable satisfies the
specifications. Use a
shielded twisted-pair wire
cable or a screened twisted-
pair cable with a conductors
2
of at least 0.12 mm
Turn OFF the power supply
to the servo system.
Check the length of the
Encoder Cable.
Continued from previous page.
Correction
Reduce the load so that
the moment of inertia ratio
or mass ratio is within the
allowable 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 Servomotor.
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.
.
The Encoder Cable length
must be 50 m max.
Continued on next page.
Reference
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5
5-45