YASKAWA Sigma-7-Series Product Manual page 126

5.7 Troubleshooting Based on the Operation and Conditions of the Servomotor
Problem
Abnormal
Noise from
Servomotor
Servomotor
Vibrates at
Frequency
of Approx.
200 to 400
Hz.
5-46
Possible Cause
Turn OFF the power supply
Noise interference
to the servo system.
occurred because the
Check the Encoder Cable to
Encoder Cable is dam-
see if it is pinched or the
aged.
sheath is damaged.
Turn OFF the power supply
The Encoder Cable to the servo system.
was subjected to Check to see if the Encoder
excessive noise inter- Cable is bundled with a
ference. high-current line or installed
near a high-current line.
There is variation in the
Turn OFF the power supply
FG potential because
to the servo system.
of the influence of
Check to see if the
machines on the Ser-
machines are correctly
vomotor side, such as
grounded.
a welder.
There is a SERVOPACK Check to see if there is
pulse counting error noise interference on the
due to noise. signal line from the encoder.
Turn OFF the power supply
to the servo system.
Check to see if vibration
The encoder was sub-
from the machine occurred.
jected to excessive
Check the Servomotor
vibration or shock.
installation (mounting sur-
face precision, securing
state, and alignment).
A failure occurred in the
–
encoder.
Check to see if the servo
The servo gains are not
gains have been correctly
balanced.
tuned.
The setting of Pn100 Check the setting of Pn100.
(Speed Loop Gain) is The default setting is Kv =
too high. 40.0 Hz.
The setting of Pn102 Check the setting of Pn102.
(Position Loop Gain) is The default setting is Kp =
too high. 40.0/s.
The setting of Pn101
Check the setting of Pn101.
(Speed Loop Integral
The default setting is Ti =
Time Constant) is not
20.0 ms.
appropriate.
The setting of Pn103
(Moment of Inertia
Check the setting of Pn103.
Ratio or Mass Ratio) is
not appropriate.
Confirmation
Replace the Encoder
Cable and correct the
cable installation environ-
ment.
Correct the cable layout so
that no surge is applied by
high-current lines.
Properly ground the
machines to separate
them from the FG of the
encoder.
Turn OFF the power supply
to the servo system.
Implement countermea-
sures against noise for the
encoder wiring.
Reduce machine vibra-
tion. Improve the mounting
conditions of the Servomo-
tor.
Turn OFF the power supply
to the servo system.
Replace the Servomotor.
Perform autotuning with-
out a host reference.
Set Pn100 to an appropri-
ate value.
Set Pn102 to an appropri-
ate value.
Set Pn101 to an appropri-
ate value.
Set Pn103 to an appropri-
ate value.
Continued from previous page.
Correction Reference
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