YASKAWA SGD7S Product Manual page 499

14.4 Troubleshooting Based on the Operation and Conditions of the Servomotor
Problem
Dynamic
Brake Does
Not Operate
Abnormal
Noise from
Servomotor
14-58
Possible Cause
The setting of Pn001 =
n.X (Servo OFF or
Alarm Group 1 Stopping
Method) is not suitable.
The dynamic brake resistor is
disconnected.
There was a failure in the
dynamic brake drive circuit.
The Servomotor vibrated
considerably while perform-
ing the tuning-less function
with the default settings.
The machine mounting is not
secure.
The bearings are defective.
There is a vibration source at
the driven machine.
Confirmation
Check the setting of
Pn001 = n.X.
Check the moment of
inertia, motor speed, and
dynamic brake frequency
of use. If the moment of
inertia, motor speed, or
dynamic brake frequency
of use is excessive, the
dynamic brake resis-
tance may be discon-
nected.
−
Check the waveform of
the motor speed.
Turn OFF the power sup-
ply to the servo system.
Check to see if there are
any loose mounting
screws.
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.
Continued from previous page.
Correction Reference
Set Pn001 = n.X
−
correctly.
Turn OFF the power
supply to the servo
system.
−
Replace the SERVO-
PACK. To prevent dis-
connection, reduce the
load.
There is a defective
component in the
dynamic brake circuit.
Turn OFF the power
−
supply to the servo
system.
Replace the SERVO-
PACK.
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 8-11
If the situation is not
improved, disable the
tuning-less function
(i.e., set Pn170 to
n.0) and execute
autotuning either with
or without a host refer-
ence.
Tighten the mounting
−
screws.
−
Align the coupling.
−
Balance the coupling.
Replace the Servomo-
−
tor.
Consult with the
−
machine manufacturer.
Continued on next page.