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View Full Version : "Electricity from the Ground Up." or "Why would I want 3-phase?"



jemelby
12-13-2004, 10:28 AM
<preface>
By now, many of you have become familiar with my esoteric, and oft nitty questions about the Shopbot. I have learned quite a bit about software, production proccesses, work flow and how the SB works. While my life after military retirement is still looking rather fluid, it gets a bit more solid every day. Thanks for everything.
</preface>

Today, I am considering what kind of power requirements my shop will have. I have the advantage of startring "from the ground up." This means I have an opportunity many wood workers only dream of. I get to design my structure with consideration for dust collection, layout, lighting, and of course... electrical distribution.

I understand the advantages of 220 vs 110, and 220v is a no brainer. I even understand a bit about single-phase vs three-phase current.

The following are questions I have asked myself, and I would appreciate your experiences and input on them. Keep in mind, while a shopbot may very well be the centerpiece of my shop, it will share space with a 5HP Unisaw, planer, a mother of a dust collection system, and much more.

- Do I need 220v, three-phase juice for my shop?
- Can I get it anywhere, or does it have to exist on the street?
- How much can I expect to save in electric bills and tool wear?

I understand that these questions require specific details for specific answers. I'm looking more for opinions and theories to help me make up my mind. I tend to over do things. A lifetime in the military has taught me that battle should be avoided unless you can be sure of force superiority. When I begin assaulting various hardwoods and sheet goods, I want to be assured of Victory!

Brady Watson
12-13-2004, 01:15 PM
James,
1. No..you don't NEED 3ph in your shop

2. No, you definately can't just call up the utility company and tell them that you want 3ph. Yes, it needs to already be on the street. For the most part, you are not going to find 3ph in a residential neighborhood. I lucked out here in NJ and am one of 2 on my block that has exsting 3ph (residential/commercial zoned)

3. You would probably save no more than $25 a year in utilites. The unseen savings is on new and used equipment because you can run 3ph where many people cannot unless they run a rotary phase inverter/converter. Plus, if you are buying new, almost every application has a choice for single or 3 phase.

-Brady

jthelen
12-13-2004, 02:45 PM
I live one block from 3 phase in Minnesota.
I called a couple years ago and they wanted about $12,000 to bring it the one block to me.

ron brown
12-13-2004, 06:09 PM
I've built and run shops single phase and 3PH. It is a "no brainer"... go 3 phase if you can. The wiring is 1/3 lighter, the motors have no capacitors to fail, industrail machinery with 3PH motors are not desired by home shop folks, the motors are less expensive to find used, VFD converters running 3PH are less expensive than single phase converters. The list is near endless IMO.

I doubt any electricity will be saved. In fact, the larger motors you find surplus will probably cause you to upgrade older tools and use even more electricity.

Your milage and attiude may differ.. but you probably don't drive the same road.

Ron

elcruisr
12-13-2004, 10:27 PM
I'm with Ron. I've worked with it and without it and I'll take the three phase power for a serious shop any day. Indusrial tools with industrial three phase motors tend to have higher horse power. That's for a reason which is often played out in faster production. Faster production equals dollars if you are into any sort of production numbers at all. My commericial electrician also informed me during our shop building phase that he sees far fewer repair orders for three phase equipment than he does for single phase as well.

Eric

johnnie53
12-15-2004, 09:32 AM
I have a 10hp Rotary Phase Converter to run my 9 hp sliding table saw, 7.5 hp wide belt and my edge bander. It works great,going well over 10 years now. If you decide to buy a new or a used woodworking machine that pops up(deal of a lifetime on ebay) you can buy it and use it.

jemelby
12-15-2004, 07:09 PM
So lemme see if I got this straight...

• Commercial 3PH Power is not terribly easy to come by. You have to be in the right place, or be willing to shell out some green to make where you are "the right place."

• You can make you own 3PH power with a "rotary phase converter."

• 3PH power is significantly superior to 1PH power based on the excellent points made in this thread.

Having lived in Europe for a number of years, I am very familiar with converting 220v power to 110v with a step down converter. I am also very familiar with the waste heat ($$$) these create. I had to take a hard look buying 220v versions of appliances, or paying for alot of wasted electricity and using my US spec stuff.

Is there a similar choice when making my own 3PH power? Is there a significant amount of wasted power? I am real keen to have 3PH equipment, but without even knowing for sure what state I will set up shop in, I can't be sure if I'll have 3PH power available. It will certainly be a consideration in site selection.

Thanks for the input thus far.

richards
12-16-2004, 09:21 AM
Here are web sites that explain 3-phase power:

www.faqs.org/faqs/electrical-wiring/part2/section-10.html (http://www.faqs.org/faqs/electrical-wiring/part2/section-10.html)

www.faqs.org/qa/qa-5276.html (http://www.faqs.org/qa/qa-5276.html)

www.team.net/www/shop-talk/hm3phase.html (http://www.team.net/www/shop-talk/hm3phase.html)

desimulacra
12-16-2004, 05:57 PM
If I had the choice I would take a 3 phase shop over a single anytime, for the excellent reasons listed above. But if you don't wire in 3-phase a converter can be very cheap and only a little trouble to DIY or you can just buy one ready to go. The biggest factor, in my opinion, would be if your shop is a hobby *(lean to single phase) or vocation (lean to 3-phase)Here is an excellent site to explain the differences.
http://home.att.net/~waterfront-woods/Articles/phaseconverter.htm