frequency drive versus rotary phase converter

[olderkesi]

I would like to run a 5hp 3 phase motor for a table saw in mt home shop. I have single phase service and can have 220 and 110 in my shop.

I was planning on using a rotary phase converter to generate 3 phase power. However, I read a note on a discussion site saying a Frequency Drive was a better and cheaper way to go. Does anyone have information or feedback on this? Eventually I will have other 3 phase motors to run also but none larger than 5 hp unless it is a 7.5 hp for an air compressor.

If a frequency drive is the way to go how do I know the size and where do I purchase one?

Thanks, Olderkesi

 

[aolalde]

olderkesi:

This subject has been widle discussed in thread 237-98395 and a lot of related threads referenced in it.

 

[swall]

Yes, olderkesi, check out those other threads.When I went through this, I found little cost difference in the rotary converters vs the VFD's, assuming you bought "name brand" stuff. But there are lots of places that have bargain basement VFD's, it seems.

 

[jraef]

Two comments to add, noting that indeed this has been discussed at length in this forum previously.

1) You can get a slightly different opinion on this, which may be more practical for you as a homeowner / hobbiest, from this forum

http://practicalmachinist.com/

Click on the Lathe icon, then go to the Phase Converter and VFD Forum. The posters in there are typically home machine users like yourself (whereas most of us are engineers and techies) and offer a slant on this issue that I have learned from myself.

2) If you plan on adding future 3 phase machines, the Rotary Phase Converter (RPC) route may be best for you. Thge VFD is a good solution for one drive running one motor, or even several motors (with proper precautions) as long as they all run at the same time. What you CANNOT do with a VFD is to have it running one motor, then switch another one on later. You can do that with a RPC.

"Venditori de oleum-vipera non vigere excordis populi"