Temporary Drive For My Mill

[Kernbigo]

you can't use a vfd with a single phase motor

 

[kingmt01]

Yes you can. A VFD adjust the frequency which adjust the speed. Best option is a DC motor. Not all motors can't run at a different frequency without getting hot & burning up tho. If you run a 3 phase motor from single phase power your only getting about 2/3 of its rating. So a 3HP is only going to be about 2HP.

A VFD is to adjust Hz where a phase converter is what deals with the last leg in the motor that isn't being used. However the VFD with a phase converter can do both jobs. Sorry but that is about the extent of my knowledge on them.

 

[John Hasler]

you can't use a vfd with a single phase motor

You could use a VFD with a capacitor-start induction-run single-phase motor. You'd always have to start at 60Hz and you'd not be able to use the full speed range especially at the low end (and reverse on the VFD would do nothing). You should be able to run any single-phase AC motor from a VFD as long as you never vary the frequency from 60Hz, but why bother?

The VFD might also not be happy about one phase being open.

 

[kingmt01]

The extent of my knowledge is what I have read & not hands on with VFD & single phase AC motors. I do see them on eBay built for single phase in & out.

 

[AaronD]

I have seen these on ebay. Never really investigated as all my equipment is 3 phase, each with their own vfd. http://www.invertekdrives.com/variable-speed-drives/optidrive-e2-single-phase/

 

[AaronD]

http://www.emainc.net/newsletter/vfd-for-single-phase-induction-motor/

Both links posted advise that these are not for high starting load. Only recommend use in fans and pumps. Also cannot be used with centrifugal switch start motors.

 

[John Hasler]

The extent of my knowledge is what I have read & not hands on with VFD & single phase AC motors. I do see them on eBay built for single phase in & out.

I see that Invertek markets a VFD for PSC motors.

 

[magu]

So all of that to circle around to it really isn't practical or everyone would be doing it, and that is why I want to upgrade to 3 phase eventually.

 

[kingmt01]

To reach there own. Most people I talk to says it isn't piratical to use a 3 phase motor if you only have single phase power.

I remember as a kid one of my neighbors did woodwork & had 3 phase motors on his tools. He ran two machines at one time to complete the circuit. If I remember right he would spin one by had then go over & start the other then turn the first one on.

I just got my first 3 phase motor a few days ago & waiting on my VFD so I'll let you know what I think about it after I've had some time to decide. I hate the idea of only having 2HP on a machine that is supposed to have 3HP.

 

[AaronD]

The 2/3rds hp "rule" is only true when using a static phase converter. A 3 hp vfd will produce 3 hp.