YASKAWA SGD7S Product Manual page 466

12.5 Troubleshooting Based on the Operation and Conditions of the Servomotor
Problem
Dynamic
Brake Does
Not Operate
Abnormal
Noise from
Servomotor
12-60
Possible Cause
The setting of Pn001 =
n.X (Motor Stopping
Method for Servo OFF and
Group 1 Alarms) is not suit-
able.
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 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.
Noise interference occurred
because an I/O signal cable
is too long.
Noise interference occurred
because of incorrect Encoder
Cable specifications.
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.
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
cables or screened
twisted-pair cables with
conductors of at least
2
0.12 mm (stranded wire).
Check the lengths of the
I/O signal cables.
Check the Encoder Cable
to see if it satisfies speci-
fications. Use shielded
twisted-pair cables or
screened twisted-pair
cables with conductors of
2
at least 0.12 mm
(stranded wire).
Continued from previous page.
Correction Reference
Set Pn001 = n.X
–
correctly.
Replace the SERVO-
PACK. To prevent dis-
–
connection, reduce the
load.
There is a defective
component in the
dynamic brake circuit.
–
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
page 8-12
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.
Continued on next page.