Delta Electronics VFD007S23A manual Low Voltage Lv

Chapter 7 Troubleshooting VFD-S Series

7.4 Low Voltage (Lv)

Low voltage

Is input power correct? Or power cut, Yes
including momentary power loss						Restart after reset
	No
Check if there is any malfunction		Yes
					Change defective component
component or disconnection in					and check connection
power supply circuit
	No
Check if voltage is			No		Make necessary corrections,
					such as change power supply
within specification
					system for requirement
	Yes
Check if there is heavy load				Yes	Using the different power
with high start current in the					supply for this drive and
same power system					heavy load system
	No						No
Check if Lv occurs when		Yes
						Suitable power
breaker and magnetic						transformer capacity
contactor is ON

No

Check if voltage between +1/+2

and - is greater thanNo 200VDC (for 230V models) 400VDC (for 460V models)

517VDC (for 575V models)

Yes

Yes

Maybe AC motor drive has malfunction. Please contact DELTA.

Control circuit has malfunction or misoperation due to noise. Please contact DELTA.

Revision August 2006, SE08, SW V2.61 7-3