Hey folks, could somebody tell me about single phase vs 3 phase VFD's.  I could swear I had my 220 line hooked up for single phase, but HSD sent me a 3 phase VFD.  Is there something I can do to use this, or do I need to send it back?

Barry

Some VFD's like some models of the small Danfoss VLT2800 series can be hooked up to either 3-phase or single phase. This is stated in the VFD manual. If the manual says the VFD is to be hooked up to 3-phase without mention single phase it is probably not able to function correctly if hooked up to single phase only.

Barry, are you hooking it up to be single phase in 3 phase out? Most I have seen can do this but it will need to be rated at 150%. If you have a 3 HP VFD it can probably push a 2 HP 3 phase motor if the primary is single phase.


If you have all of that figured out already, you will need an analog out from Mach for it to control the Freq of the VFD. Most BOB makers offer an analog out or spindle speed board. You could also use feedback from the spindle to Mach to show you the spindle speed and use a potentiometer.

Brett

I gotta tell you the service from HSD sucks.  I had the salesperson choose the VFD I'd need, and looks like he chose wrong.  Worse yet, it came without a manual.  When I asked for the manual, he sent one from  "SIRCO", which it looks like have the same maker, but completely different model numbers.  There was no explanation, argh.  I don't recommend ordering from these guys ever after this.

Sure enough, the VFD is incorrect.  I have to ship it back and get a different one.  This same company lost my order twice before too.  It seems they don't want to be in business.

Ive hooked up many VFDs, and all of them Ive seen are designed for 3 phase in and out, but work fine with single phase in. They must be de-rated about 1/3 or so, but they will work just fine.

You definitely need the correct manual, because most of these have about a thousand parameters you can set and without the doc s you havent got a chance to get it right.