Hello,

I need some help with a VFD.

When I power up the unit, the error ( OI.AC ) is displayed, even with the motor and cables disconnected.,

Can someone please advise

Thanks

 

A make and model would help!
And possibly a link to the manual!
Max.

 

I had 2 do that just this last week
One was it was too hot where it was installed. And one was the guy I let wire up the motor didn't tape the butt splices up good.
I just did and new carwash 32 VFD the room where there at hit about 110 f
The one that shuts down has no cabinet fan.
The room did have air condition they figured it save money not to have it new air going in this week.

Your case tho with no motor it should not show error or most don't
read the manual and reset the VFD

 

Hello

VFD: EMERSON
Model: M200 ( 45/55 Kw ).

Motor is Ok, and ables where tested and are ok too.
Both motor and cables are disconnected from the vfd.

 

It would appear you may have a defective IGBT on the output, that error should only show when motor and cables are connected to the 3ph output.
Max.

 

Thanks Max.

I'm going to check the IGBT module.

Best Regards

 

Is there a braking resistor fitted?
Max.

 

Hello Max.

No braking resistor.

DS

 

Then it seems to come back to the power output device(s) shot.
Max.

 

Hello Max,

Can you please give me an opinion related to, what should I check in the equipment.

regards

 

You would have to inspect the IGBT or other power devices for failure, short circuit etc on the output.
Max.

 

Hello Max,

Can you help me with this.
I've read the manual, off this equipment, but I'm having some difficulties on resetting this error, can you please advise.
this software is not the most intuitive.

Thanks,
DS

 

As I mentioned, If the output is disconnected, there should not be an OL error, if it does it at switch on without any thing on UVW, then it points to a short in the VFD output, if so you cannot reset it until the defect/fault is resolved.
Max.

 

went through this a while back.

http://www.efesotomasyon.com/html/emerson/CTTG109.pdf

 

Hello,

Thank you for the help, and thanks to all of you.

Best regards,

DS