7.4 Low Voltage (Lv)

Low voltage

Chapter 7 Troubleshooting |VFD-B Series

Is input power correct? Or power cut, Yes

including momentary power loss

No

Restart after reset

Check if there is any malfunction Yes

component or disconnection in

power supply circuit

No

Change defective component

and check connection

Check if voltage is

No

within specification

Yes

Make necessary corrections,

such as change power supply

system for requirement

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

Check if Lv occurs when Yes

breaker and magnetic

contactor is ON

No

Check if voltage between +1/+2

and - is greater than

No

200VDC (for 230V models)

400VDC (for 460V models)

517VDC (for 575V models)

Yes

No

Suitable power

transformer capacity

Yes

Maybe AC motor drive has malfunction.

Please contact DELTA.

Control circuit has malfunction or

misoperation due to noise. Please

contact DELTA.

Revision July 2008, BE16, SW V4.08 & V5.00

7-3