YASKAWA SGMJV User Manual page 357

Problem Probable Cause
Servomotor Wiring connection to servomotor is
Speed Unstable defective.
Speed control: Speed reference
input is incorrect.
Torque control: Torque reference
Servomotor input is incorrect.
Rotates Without
Reference Input
Speed reference offset is incorrect.
Position control: Reference pulse
input is incorrect.
A SERVOPACK fault occurred.
Improper Pn001 setting
Dynamic Brake
DB resistor disconnected
Does Not Operate
DB drive circuit fault
The servomotor largely vibrated
during execution of tuning-less
function.
Mounting is not secured.
Bearings are defective.
Vibration source at the driven
machine
Abnormal Noise
from Servomotor
Noise interference due to incorrect
input/output signal cable specifica-
tions
Noise interference due to length of
input/output signal cable.
Noise interference due to incorrect
encoder cable specifications.
Noise interference due to length of
encoder cable wiring
Noise interference due to damaged
encoder cable
Excessive noise to the encoder
cable
10.3 Troubleshooting Malfunction Based on Operation and Conditions of the Servomotor
Investigative Actions
Check connections of main circuit
cable (phases-U, -V, and -W) and
encoder connectors.
Check V-REF and SG to confirm if
the control method and the input are
agreed.
Check V-REF and SG to confirm if
the control method and the input are
agreed.
The SERVOPACK offset is
adjusted incorrectly.
Check Pn200.0 reference pulse
form or sign + pulse signal.
−
Check the setting of parameter
Pn001.0.
Check if excessive moment of iner-
tia, motor overspeed, or DB fre-
quently activated occurred.
−
Check the servomotor speed wave-
form.
Check if there are any loose mount-
ing screws.
Check if there is misalignment of
couplings.
Check if there are unbalanced cou-
plings.
Check for noise and vibration
around the bearings.
Check for any foreign matter, dam-
age, or deformations on the machin-
ery's movable parts.
The input/output signal cables must
be tinned annealed copper twisted-
pair or shielded twisted-pair cables
with a core of 0.12 mm
Check the length of the input/output
cable.
The encoder cable must be tinned
annealed copper twisted-pair or
shielded twisted-pair cables with a
2
core of 0.12 mm min.
Check the length of the encoder
cable.
Check if the encoder cable is dam-
aged or bent.
Check if the encoder cable is bun-
dled with high-current line or near a
high-current line.
Corrective Actions
Tighten any loose terminals or con-
nectors.
Correct the control mode selection
parameter, or the input signal.
Correct the control mode selection
parameter, or the input signal.
Adjust the SERVOPACK offset.
Correct the control mode selection
parameter, or the input signal.
Replace the SERVOPACK.
Correct the parameter setting.
Replace the SERVOPACK, and
lighten the load.
There is a defective component in
the DB circuit. Replace the SER-
VOPACK.
Reduce the load so that the moment
of inertia ratio becomes within the
allowable value, or increase the
load level or lower the tuning level
for the tuning-less level setting
(Fn200).
Tighten the mounting screws.
Align the couplings.
Balance the couplings.
Replace the servomotor.
Contact the machine manufacturer.
Use the specified input signal wires.
2
min.
The input/output cable length must
be no more than 3 m.
Use the specified encoder cable.
The encoder cable must be no more
than 20 m.
Replace the encoder cable and mod-
ify the encoder cable layout.
Correct the encoder cable layout so
that no surge is applied.
10
10-25