YASKAWA UAK series User Manual page 280

11 Inspection, Maintenance, and Troubleshooting
11.2.3 Troubleshooting of the Servo Drive Alarms
Alarm:
Alarm Name
A.BF4:
System Alarm 4
A.C10:
Servo Overrun
Detected
(Detected when the ser-
vomotor power is ON.)
A.C2A:
Pulse Encoder Phase
C Error/Pulse Error
A.C3A:
Pulse Encoder Phase
A Disconnection
A.C3B:
Pulse Encoder Phase
B Disconnection
A.C3C:
Pulse Encoder Phase
C Disconnection
A.C50:
Phase C Not Detected
A.C50:
Magnetic Pole
Incorrect Detection
A.C51:
Overtravel Detection
at Polarity Detection
11-26
Cause
SERVOPACK failure
The order of phases U, V, and W
in the servomotor wiring is incor-
rect.
Encoder failure
SERVOPACK failure
An error occurred in the feedback
pulse count of the pulse encoder.
Malfunction caused by noise.
The signal line for phase A of the
pulse encoder is disconnected.
The signal line for phase B of the
pulse encoder is disconnected.
The signal line for phase C of the
pulse encoder is disconnected.
The phase C signal of the pulse
encoder is not wired correctly.
Pulse encoder error
The parameters are not set cor-
rectly.
Noise is entering on the encoder
signal.
An external force was applied to
the motor's rotor.
The resolution of the encoder is
too low.
An overtravel signal was detected
during magnetic pole detection.
Investigative Actions
−
Check the servomotor wiring.
−
−
Check the signal wiring of the pulse
encoder.
Improve the noise environment,
including the wiring and installa-
tion, and check to see if the alarm
occurs again.
Check the signal wiring of the pulse
encoder.
Check the signal wiring of the pulse
encoder.
Check the signal wiring of the pulse
encoder.
Check the signal wiring of the pulse
encoder.
Check the phase C signal of the
pulse encoder.
Check the encoder specifications
and the feedback signal status.
Check to see if the FG on the servo-
motor is connected to the FG on the
SERVOPACK and that the FG on
the SERVOPACK is connected to
the FG on the power supply. Also,
make sure that the encoder cable is
shielded properly. Check to see if
the detection command is being
given repeatedly in the same direc-
tion.
−
−
Check the overtravel position.
(cont'd)
Corrective Actions
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.
Confirm that the servomotor is cor-
rectly wired.
If the alarm still occurs after turning
the power OFF and then ON again,
even though the servomotor is cor-
rectly wired, the servomotor may be
faulty. Replace the servomotor.
Turn the power supply OFF and
then ON again. If the alarm still
occurs, the SERVOPACK may be
faulty. Replace the SERVOPACK.
Correct the wiring of the pulse
encoder.
Install the pulse encoder cable away
from the peripheral equipment, or
add a ferrite core.
Correct the wiring of the pulse
encoder.
Correct the wiring of the pulse
encoder.
Correct the wiring of the pulse
encoder.
Correct the wiring of the pulse
encoder.
The pulse encoder may have failed.
Replace the motor.
Set the power torque limit in Pn430
and the regeneration torque limit in
Pn431 correctly.
Correct the shield on the encoder
cable.
Correct the FG wiring.
Reduce the external force to about
10% or less of the motor's rated
torque.
Increase the magnetic pole detec-
tion command speed in Pn493.
Move the motor's stator to a posi-
tion where overtravel will not be
detected.