YASKAWA Σ-V Series User Manual page 275

8 Troubleshooting
Problem
Linear
Servomotor
Moves
Instantaneously,
and then Stops
Linear
Servomotor
Speed Unstable
Linear
Servomotor
Moves
Without
Reference
Input
DB (dynamic
brake) Does Not
Operate
Abnormal Noise
from Linear
Servomotor
8-30
Probable Cause
Linear servomotor wiring is incor-
rect.
Serial converter unit wiring is incor-
rect.
Linear scale wiring is incorrect.
Linear scale pitch (Pn282) is incor-
rect.
Linear scale counting up direction
and motor moving coil forward
direction do not agree.
Polarity detection is not performed
correctly.
Wiring connection to linear servo-
motor is defective.
A SERVOPACK fault occurred.
Linear scale counting up direction
and motor moving coil forward
direction do not agree.
Polarity detection is not performed
correctly.
Improper setting of parameter
Pn001.0
DB resistor disconnected
DB drive circuit fault
The linear servomotor largely
vibrated during execution of tuning-
less function (factory setting).
Mounting not secured
Vibration source on the driven
machine
Noise interference due to incorrect
I/O signal cable specifications
Noise interference due to long dis-
tance of I/O signal cable
Investigative Actions
Check the linear servomotor wiring.
Check the serial converter unit wir-
ing.
Check the linear scale wiring.
Check the setting of Pn282.
Check the directions.
Check if the value of Un004 (Elec-
tric Angle 2, angle from polarity
origin) at an arbitrary position is
between ±10 degrees.
Check connection of power lead
(phases U, V, and W) and the con-
nectors of linear scale connection
cables.
–
Check the directions.
Check if the value of Un004 (Elec-
tric Angle 2, angle from polarity
origin) at an arbitrary position is
between ±10 degrees.
Check the setting of parameter
Pn001.0 (Servo OFF or Alarm Gr.1
Stop Mode).
Check if excessive mass, motor
overspeed, or DB frequent activa-
tion has occurred.
–
Check the motor speed waveform.
Check if there are any loosen
mounting screws.
Check the machine movable section
for foreign matter, damage or defor-
mity.
The specifications of I/O signal
cables must be:
Twisted-pair or twisted-pair
shielded wire with core
2
0.12 mm min. and tinned annealed
copper twisted wire.
Check the I/O signal cable length.
Corrective Actions
Correct the linear servomotor wir-
ing.
Correct the serial converter unit
wiring.
Correct the linear scale wiring.
Correct the setting of Pn282.
Change the setting of Pn080.1
(Motor Phase Selection).
Match the linear scale direction and
moving coil direction.
Correct the settings for the polarity
detection related parameter.
Tighten any loose terminals or con-
nectors.
Replace the SERVOPACK.
Change the setting of Pn080.1
(Motor Phase Selection).
Match the linear scale direction and
moving coil direction.
Correct the settings for the polarity
detection related parameter.
Correct the setting of parameter
Pn001.0.
Replace the SERVOPACK, and
reconsider the load.
DB circuit parts are faulty.
Replace the SERVOPACK.
Reduce the load so that the mass
ratio becomes within the allowable
value, or increase the load level or
lower the rigidity level for the tun-
ing-less level setting (Fn200).
Tighten the mounting screws.
Contact the machine manufacturer.
Use the specified I/O signal cables.
Shorten the I/O signal cable length
to 3 m or less.