3 phase converter ok ?

   / 3 phase converter ok ? #1  


Elite Member
Apr 12, 2011
I'm not particularly knowledgable about electricity. Here is what I have and looking to do. I have a 200 amp service now and I'm looking at a piece of equipment that requires 3phase. Running 3 to my home would be very ..very expensive, likely 50k +\-. One of the electricians I spoke with said a phase converter may be the answer. He said I needed the motor size and electric requirements to order the correct size converter. My question is weather there are potential drawbacks to using a converter ? ..Any electricians on TBN ?
   / 3 phase converter ok ? #2  
There are several ways to convert single phase to three phase. Add-A-Phase, Roto-phase, and inverters. It depends on what kind of equipment you are running and wether or not the amp load varies as to which one is best.
   / 3 phase converter ok ? #3  
I have been using a phase converter for over 10 years to run a large lathe and a 50 ton Ironworker, both have 5 hp motors.
I built my own Static Converter from instructions on line for $45. Rotary Converters cost a lot more.
With a Static Converter for example, a 3 hp motor will only produce 2 hp due to the conversion.
My tools don't run at 100% but they do very well for me.
   / 3 phase converter ok ? #4  
Here's a place that sells inverters that are made specifically to be phase converters.
   / 3 phase converter ok ? #5  
I'm not an electrician either, but had the same basic problem/concern. We installed a 35 hp rotor phase converter about 7 years ago to run our PC oven. So far it hasn't given any problems.
   / 3 phase converter ok ? #6  
If you need three phase for a smaller, single motor, a VFD is the best answer IMO.

If you have more than one machine to run, a rotary is more cost effective.

I am Not a fan of a static convertor due to less power. A rotary gets you full power, as it is basically a static convertor, starting an upsize pony motor to build the third leg.

As to drawbacks...convertors, not have nice equal voltages. No big deal for motors, but electronics might not work right.
   / 3 phase converter ok ?
  • Thread Starter
It is a electronic application. It a a large format UV printer. I'm going to ask the manufacturer is a converter is even a option with their unit. I don't want to void any warranty and can't compromise any power requirements.
   / 3 phase converter ok ? #8  
What is the power requirement?

I agree, get with the MFG. But a VFD has a much better voltage balance than a rotary. If done right, it can be even better and cleaner than 3ph from the grid.

Does this mfg offer a single phase version?
   / 3 phase converter ok ? #9  
On somthing like that I would definitely check with the manufacturer as they can be pretty picky about phase balance.

I use to have a vfd on my small lathe but sold it when I upgraded, lot of nifty features on a vfd but never used one other then for motor control. Once you get into larger vfd the price shoots up pretty quick.

I currently use a rotary converter using a 10hp motor that my dad was able to get from work for scrap price and a control panel from Phase Craft, works great and has very clean/ balanced legs. I have less then $300 in it.
If everything works out hopefully I'll have true 3 phase in the new shop.........
   / 3 phase converter ok ? #10  
I would build an RPC with PhaseCraft controls in a minute just to convert to 3PH for most motors (constant speed/load) and go right to VFD to gain speed control on machine spindles, but use neither for plotter, printer, or CNC machine/table if I could help it.

If you'd pay Cadillac money to get Roll Royce-class waveform and phase balance that your poco only promises there is a 'best' for this IMO and that's a brand called PhasePerfect. I'd be shocked if any maker advised against PP, would expect to see it recommended #1 if anything were esp if seeking isolation from electrical 'noise'/effects generated elsewhere onsite (on your meter).

btw, PP in not just another big biz gadget foisted on everyday users by distorting the benefits out of proportion to our smaller power demands. Lab quality power for delicate electronics is out there. You wouldn't by a cheapo surge suppressor for a valuable tool, with PP you might not need one either. Google-up and find out more.

Phase Perfect

(no connection to them ..)