I'm interested in building a 3-phase rotary converter to power 3 to 5 HP. motors in my home shop. (Table saw, Milling machine) (240VAC)
I occasionally come across used 10-20 hp. motors in my line of work, and I thought maybe I could put one of them to good use.
Does anyone know of plans available on the web anywhere?
Is a 20 horse (or so)motor too big for this use?
You have everything you need. Wire slave motor two legs to the power supply switch and all three legs to the machine inbox. Put a pully on the slave motor. Turn on slave power, kick the pully circumference, and the slave will spin up. Then use your machine switch as always.
20 Hp is PLENTY. I run a 3 Hp hor mill using a 1 Hp slave.Dave Adams wrote:
Look through here:
The best article I've seen is by Bob Swinney (regular here) and was published in Home Shop Machinist magazine. Village Press will send you a back issue.
I'm not a EE type and I've built three units now. Piece of cake. Start looking for your main components while you wait for the articles. Motor, capacitors both start and run, potential relay, electrical box. 10 hp is plenty big, but the only problem with larger units is needing larger wire and fusing. Oversized units provide extremely stable high quality three phase conversion.
Example:
Hoyt the typical rule is that the idler motor should be
1.5 times the hp rating of the machine it's running. You might have some trouble starting or plug reversing the mill possibly. Did you put any correction capacitors in to help things out?Jim
================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================
I have plans on my website for a 3 hp self start balanced rotary phase convertor. It is easy enough to upscale for a larger motor, just by increasing ther contactor and capacitor sizes. It was constrructed with the help of this newsgroup over two years ago and has been kicking butt ever since. Bob Sweenys advice both here and in his article in HSM, as well as others was followed in its construction.
But there is a ton of info on home brew phase copnvertors out on the web, some good some great some well they leave a lot to be desired. They are not hard to make. Visit my website:
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