three phase converter

bandmiller2 · November 16, 2007, 06:49:35 AM

Shopteacher please explain capacitors on the third leg of a running rotary converter.How many mf's,old dog needs new tricks. Thanks Frank C.

jason.weir · November 16, 2007, 09:56:35 AM

All you ever need to know

http://home.att.net/~waterfront-woods/Articles/phaseconverter.htm

I have built one, so if you have any more questions ask away.

-Jason

Don P · November 16, 2007, 07:34:57 PM

I'm running a couple of what I think are called power factor capacitors between a line leg and the created leg. If I remember setting it up correctly I added caps until there was no improvement in balancing on an ammeter. I think you're supposed to be a little lagging rather than pushing with those, not sure bout that ???.

shopteacher · November 16, 2007, 08:50:01 PM

Here are a couple links for building a rotary converter. I was going to post a schematic of the one I built, but my scanning software expired and I can't scan anything.
http://www.metalwebnews.com/howto/phase-converter/phase-converter.html

http://www.metalwebnews.com/howto/ph-conv/ph-conv.html

http://home.att.net/~waterfront-woods/Articles/phaseconverter.htm

http://www.laserfx.com/Backstage.LaserFX.com/Hobby/PhaseConvert.html

If you read these articles and follow their schematic you can build yourself a three phase converter. Most central air conditioner units use a run and start capacitor and relay in the compressor unit. Even window units have smaller run capacitor that can be used to refine the voltage being generated in the third leg. My unit is using a total of 150 UF on one leg and 80 UF on the other. My start capacitor is a 1000 UF that is automatically disconnected through the use of a potential relay. The forth link has a number for a mars potential relay. These can be purchased through a refrigeration supply or an electronic supply house or found in refrigeration and A/C units. I have many parts for these units.

bandmiller2 · November 17, 2007, 07:31:37 AM

Wow guys so much info. so quick thank you.One reason I asked is I just picked up a high pressure [3500psi] air comp. with a 5hp 3 phase motor.I have a 5hp single phase motor 220 v 25amp would it be cheaper to run using a static or rotary converter or the 5hp single phase.Many thanks Frank C.