The Stovebolt Site Forums The Shop Area The Tool Chest 3 Phase Power to my residence

I have noticed that used 3 phase air compressors seem to a bargin in dollors per cfm. I am moving soon and called the electical company to see if it would be avaialbe at the new place. They left me a message this am and I'll summarize it using round numbers. The closest three phase was 2.5 miles away or about 11,000 feet. This would cost $90,000 to bring out, but I could pay for over 18 months at $5,000 a month. Pretty cool huh? I have decided to get a single phase compressor, even if it costs a little more.

Wow....what a deal! There are devices called AC Inverters or frequency drives that allow you to generate the third phase from a single phase input.

These are NOT rotary/static converts but solid state, programmable drives. The abound on e-bay and are pretty cheap in the small HP's.

I have several in my shop powering a three phase lathe, Bridgeport and drill press. There is no 'free lunch' electrically speaking, but one of these devices allows you to find a slightly larger air compressor at the dime-a-dozen three phase price.

Stuart

The 3 phase inverter for my lathe cost about $100.

Cletis,

I'm guessing you find that a bargain. With an inverter you can get over speed up to 300hz if you want, dynamic braking, acceleration and deceleration and about a million other things, including motor protection.

Want your lathe or mill to go faster or slower, presto, turn the little speed pot you installed next to the start/stop station.

These things are very cool.

Stuart

I went the other way, I have one commercial rotary phase converter, which is nothing more than a static converter plus a 5 HP idler motor. This would allow you to drive anything in your shop up to something less than the 5 hp.
I have also made a unit, and there are free plans on the internet for making anything from a simple static unit to a fully automatic unit. I will be making another larger unit to drive my 3 phase welder when I finish building my shop. This unit will have a 10 hp idler, or 2 5 hp units if I can't find a 10.
I have some links, if there is someone interested in learning how they work or want to make one.
Bob

Sounds like a similar problem, we are about 2 miles away from 3 phase, and when we asked 5 years ago it was $24,000 to get it here.

I have two converters, one commercially built 10 HP rotary that works fine.
When I got my 15 HP lathe I needed more, so I built a rotary 15 HP converter at very little expense, and will do it again if I ever need another converter.

We have a total of about 40 HP worth of three phase tools, and occasionally will run over 30 HP at a time.
We started with the converter, and as the shop grew and tools got bigger we wanted to upgrade to real power, but for the cost it's not worth it.

Grigg

A lot of woodworkers are using these:
http://www.factorymation.com/s.nl/it.A/id.198/.f?category=32

However, you probably want a bigger than 3 hp unit, but the Westinghouse/TECO drives are a pretty good bargain.