7 Troubleshooting
YASKAWA ELECTRIC
TOBP C730600 37B 1000-Series Option PG-X3 Installation Manual
27
The PG encoder is disconnected
or is not wired properly, or the
PG option or PG are damaged.
• Rewire the PG encoder and make sure all wiring including shielded wiring is
properly connected
• If the problem continues after cycling power, replace the PG option or the PG
encoder.
Digital Operator Display
Fault Name
dv3
Inversion Detection
• Torque reference and acceleration are in opposite directions.
• The speed reference and actual motor speed differ by over 30% for the number
of pulses set to parameter F1-18.
Cause
Possible Solution
The Z channel pulse offset is not
set properly to E5-11.
Set the value for
Δθ
to E5-11 as specified on the motor nameplate. Replacing the
PG encoder or changing the application so the motor rotates in reverse requires
readjustment of the Z channel pulse offset.
An external force on the load
side caused the motor to move.
• Make sure the motor is rotating in the proper direction.
• Investigate problems on the load side causing motor rotation in the opposite
direction.
Noise interference along the PG
cable affecting the A channel or
B channel.
• Rewire the PG encoder and make sure all wiring including shielded wiring is
properly connected
• If the problem continues after cycling power, replace the PG option or the PG
encoder.
The PG encoder is disconnected
or is not wired properly, or the
PG option or PG are damaged.
The PG encoder rotational
direction set to F1-05 is in the
opposite direction of the motor
wiring.
Make sure motor wiring for each phase (U, V, W) is connected properly.
Digital Operator Display
Fault Name
dv4
Inversion Prevention Detection
Pulses indicate that the motor is rotating in the opposite direction of the speed
reference. Set the number of pulses to trigger inverse detection to F1-19.
Note:
To avoid nuisance faults, be sure to disable inverse detection in applications
where the motor may rotate in the opposite direction of the speed reference. Set
F1-19 to 0 to disable this feature.
Cause
Possible Solution
The Z channel pulse offset is not
set properly to E5-11.
• Set the value for
Δθ
to E5-11 as specified on the motor nameplate.
• If the problem continues after cycling power, replace the PG option or the PG
encoder.
Replacing the PG encoder or changing the application so the motor rotates in
reverse requires readjustment of the Z channel pulse offset.
Noise interference along the PG
is cable affecting the A or B
pulse.
• Make sure the motor is rotating in the proper direction.
• Investigate problems on the load-side that may be causing the motor to rotate in
the opposite direction.
