Rotery Air Compressor.

No takers? Nobody knows anything about compressors? HMMMM Anyone... Anyone ? I know there is a couple company that will retro fit their controls but just wondered if anyone had any input or experience.. thanks.

On rotary compressors I have only seen wye start delta run. Have not yet seen a VFD.

The first question is what is a HPM motor. That does not ring any bells.

IF it is really a perm magnet 3 phase motor also called Brushless DC but more accurate Perm Mag Sunchronous Motor (PMSM) then you may have problems. The controllers for these look a lot like a VFD but the control algorythms are completely difficult. Based on my one time 5 minute trial to drive a PMSM off a off shelf VFD - which did not work - I think you may have problems.

IF motor is a "standard" asynchronous ie induction or squirrel cage then you may have success driving with standard VFD.

Dan Bentler

Usually high efficiency permanent magnet motors require special considerations for the VFD - they don't act quite like standard induction motors. Many also run at much higher speeds than standard motors. I've seen many running at close to 300 Hz.

That isn't to say you can't get a VFD from an alternate source to do the job, but it will require a lot of data FOR the supplier and you won't be using an off the shelf commodity VFD. It may not be worth it for a one-off system.

We have a couple of the Nirvana variable speed compressors. The VFD is a really special animal. We have had to have several rebuilt, and they are not really replaceable with off-the-shelf components, from my experience. If you find otherwise, please let us know!

Thanks,

I would like to say thanks for the Reply's. Apon doing some more extensive research from what you have written helped greatly. They do make drives especially for the HPM or PMAC as what most call now. Baldor, ABB to name a couple. There is a parameter which allows you to go from standard ACIM Motor to PMAC. But of course not without cost. Anywhere from $6500 to %17,000 for a 100HP or 160A. Can it be done I am sure it can. Is it worth it well that is for the higher ups to decide? New compressor 40,000 Downtime? I guess another question is Compressor manufactures what are some of your Recommendations?
If I do get the go ahead I will make sure I update the post with my findings. Thanks again
Here is a pretty good article explaining the difference between ACIM and PMAC Motors.
http://www.appliancedesign.com/articles/91215-motors-drive-decisions

Our last two screw compressors both of which are about that size are Sullairs. They have been very good. They have Cutler Hammer drives in them from Eaton they aren't marketed as such but that is what they are.

Looking at different options for getting this compressor back in working order I was looking for individual parts and came up with this.
http://www.meiinternational.com/CPN...V120TIR-VSD-Compressor-Controller-_p_504.html

I could not even buy a drive for what they quoted me. It was weird I searched for a week or better and this company did not come up till I looked for a part number on the capacitor. They rebuild the drive and if you need a controller the retrieve the program and Parameters and set it up so nothing changes and it is bolt on install..Good find.
It has opened up a lot of my time to move on to bigger and better things. I still would of liked to try it.