Delta Electronics VFD-VL manual Motor Speed cannot be Changed

Chapter 5 Troubleshooting

5.10 Motor Speed cannot be Changed

			Motor can run but
			cannot change speed
Modify the setting	Yes		Check if the setting of the
			max. frequency is too low
No				No
		If the setting of frequency			Yes
		is out of range(upper/lower)				Modify the setting
		bound

Yes	If the setting of
	Pr.04-00 to Pr.04-14
	are the same

No

No

Press UP/DOWN key to see if speed has any change

If there is any change of the signal that sets frequency (-10V-10V and 4-20mA)

Yes

Yes

No	Check if the wiring between
	MI1~MI8 to COM is correct	No

No

Yes

Connect correctly

Check if frequency for
each step is different	No
Yes

No

Check if the wiring of external terminal is correct

Yes

Change defective potentiometer

No If accel./decel. time is very long

Yes

Please set suitable accel./decel. time by load inertia

Change frequency setting

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

Revision Nov. 2008, VLE1, SW V1.03 5-7