Cheap 3-phase converter?

[Chris Padilla]

Is this crap or not? Anyone in the know know?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2995648474&category=3144

[Jim Becker]

Do some searching in the 'net...you may be able to find the same or similar plans out there "gratis". (I didn't test it, however)

[Ken Garlock]

Chris, if you look carefully at the Ebay ad, you will see that what you get is some information on 3-phase, and a starter capacitor to make a Q&D (quick an dirty) converter. Not a big deal.

Rick Christopherson has a website that goes into 3-ph conversions. It is worth reading, IMO. Phase converter (http://home.att.net/~waterfront-woods/Articles/phaseconverter.htm)

[Steve Clardy]

Is this crap or not? Anyone in the know know?

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=2995648474&category=3144

Looks ok to me. I have one similar that was built at a motor shop some years ago. I use it to run my Hempel lathe that has a 2hp and a 3hp 3-phase motor, and also run my dust collector, which is a 1 1/2hp 3-phase at the same time.
I also have one of them static boxes I got from Grizzly to run my 7 hp overhead pin router. 3-phase is the way to go sometimes, as you can pick up used 3-phase machinery dirt cheap sometimes. I also have my old 20" bandsaw on 3-phase. Steve
Ps. Overlook the dust, as I Haven't did a through cleaning lately. lol

[Rob Russell]

Chris,

If you're really interested in building a phase convertor, spend the time to go through the posts in this forum.


Practical Machinist - Phase Covertors and VFDs (http://www.practicalmachinist.com/cgi-bin/ubbcgi/forumdisplay.cgi?action=topics&forum=Phase+Converters+and+VFD&number=3&DaysPrune=1000&LastLogin=)

Rick C's site is good as a starter, but by also going through the threads - you'll not only learn how to build an RPC but how to balance it. There are some extremely knowledgeable folks who help out on that forum. By "knowledgeable", I mean as in they work in the industry and know of what they speak.

It's from that forum that I was able to get 90% of the info to design my own, self-starting, RPC. I'm using a 15 HP motor and the RPC is designed to handle a running load of 20 HP. That's a far cry more complicated than a smaller RPC because of the contactors and overloads required due to the current loads, plus I tend to overengineer things. Still, a smaller RPC could be built on the cheap if you don't want really fancy. Stay way from the static convertors - they're just a start capacitor to get the 3-phase motor spinning and then you only get about 1/2 - 2/3 rated HP out of the motor.

Rob

As far as the ebay link, Rick C's site will give you more for free than you probably get from the plans you buy on tha tauction.

Rob

[Paul Downes]

Chris, You might want to go snoop around a motor rebuild shop and or check out salvage yards. Sometimes 15hp 3 phase motors can be had cheap. A friend of mine built one that size with the help of an old motor rebuild guy. $50 for the motor and I think less than $100 for everything else.