Delta Electronics VFD-EL manual Ground Fault, Over Voltage OV, Troubleshooting

Chapter 5 Troubleshooting

5.2 Ground Fault

GFF

Ground fault

5.3 Over Voltage (OV)

Is output circuit(cable or			No
motor) of AC motor drive
grounded?
		Yes
	Remove ground fault

Maybe AC motor drive has malfunction or misoperation due to noise. Please contact DELTA.

Over voltage

Reduce voltage to	No Is voltage within
be within spec.		specification
			Yes

Maybe AC motor drive has malfunction or misoperation due to noise. Please contact with DELTA.

Has over-voltage occurred without load Yes No

No When OV occurs, check if the voltage of DC BUS is greater than protection value

YesYes

No

Reduce moment of inertia

Dose OV occur when			Increase			Yes
sudden acceleration			deceleration
stops			time
		Yes		No
	Increase		Yes
	acceleration				Increase setting time
	time
		No				Need to consider using
No
	Reduce moment of load inertia					braking unit or
						DC braking

	No
		No
Use braking unit or DC braking
	Yes

Need to check control method. Please contact DELTA.

5-2 Revision August 2008, 2ELE, V1.02