Delta MS300 Series User Manual page 611

Chapter 14 Fault CodesMS300
ID Display on LCD Keypad
79
Action Condition
Action Time
Fault Treatment Parameter
Reset Method
Reset Condition
Record
Cause
Incorrect wiring for the motor
Short-circuit at motor output due to
poor insulation wiring
Check for possible burnout or
aging insulation of the motor
Malfunction caused by
interference
The length of motor cable is too
long
Hardware failure
Fault Name
U-phase over-current
before run
(Aoc)
Action and Reset
300% of the rated current
Immediately act
N/A
Manual reset
Reset in five seconds after the fault clears
Yes
Check if the motor's internal wiring and the UVW wiring of the drive output
terminal are correct.
Check the motor cable and remove causes of the short circuits, or replace the
cable before turning on the power.
Check the motor insulation value with megger. Replace the motor if the
insulation is poor.
Verify the wiring of the control circuit and the wiring/grounding of the main
circuit to prevent interference.
Increase the AC motor drive's capacity.
Install AC reactor(s) on the output side (U/V/W).
The Aoc occurs due to the short circuit or ground fault at the output side of the
drive. Check for possible short circuits between terminals with the electric
meter:
B1 corresponds to U, V and W; DC- corresponds to U, V and W;
corresponds to U, V and W.
If short circuit occurs, return to the factory for repair.
602
Fault Descriptions
U-phase short circuit detected when the output wiring
detection is performed before the drive runs.
Corrective Actions