3phase

[Taylortractornut]

Does anyone here know of a welding vender or company that produces 3 phase pasma cutters. Last month the power company ran 3 Phase to the shop but it seems i cant get it through my suppliers head that i want a 3 phase machine. Id buy a new or used one if I could. Best reguard Taylor Lambert

 

[chim]

Here's one:

http://www.welders-direct.com/merchant2/merchant.mv?Screen=PROD&Store_Code=WD&Product_Code=1-1252-1

Is there a particular reason you want 3 phase? There appear to be some really hefty cutters running on single phase...............chim

 

[Anonymous Poster]

Miller's larger machines are either 3 phase or single phase, depending on how you connect them up.
A 3 phase machine would pull less amps, thus lowering your demand factor, big bucks when it comes to the electric bill.

 

[Anonymous Poster]

Actually, most of the welders......and this may also include plasma cutters......are only "two leg" power, so they would only use two of the three legs of your three-phase system anyway. My Miller 35 is that way....220 or 440, two leg power.........and obviously if the shop were on 440 it would be three phase. That is probably what is corn-fuzing your welding products supplier. You remember the bullet-head DC welders from the fifties....heck they go back to the shipyards of WWII.......THOSE machines were actually motor-generator sets which required THREE LEGS of three phase power. In that case, it was necessary to have a three-phase shop, either 220V or 440V three phase.

 

[wroughtn_harv]

My Miller Dialarc 250 can be wired up single or three phase. I also have a Miller Spectrum 1000 Plasma cutter that I've never hooked up because it's three phase and I've only got single in my shop, one of these days.........

Your best source for three phase is machinery auctions. You won't be bidding against many folks because few have three phase. Single phase on the other hand is what everyone else wants. So if you do buy new you'd better plan on keeping it.

 

[Taylortractornut]

My main reason for wanting a 3 phase is to keep all the local race car owners i work for from wanting to borrow it, if its a single phase machine they get agravated cause im cautious about who i loan stuff to. When they here its 3 phase they dont ask any more. Plus i like the duty cycleof a larger machine.
I had one a few years ago but i couldnt run it on my converter i built. Id rent a large 3 phase generator to run it. So now the power company needing some good PR ran it to the shop free. But i sold my plasma cutter.
Im only 23 but i worked for a compan when i was 17 in the summer as a machinist and welder they had Migs but when i die broke we welded them with an old Lincoln with the barrel type body Then we had another that was a Lincoln with the upright norrow dome i called it R2D2. The head machinist hated having to drag out all the extension cord to move it to the press room so he mounted a governed 12 horse motor to the top of an upright motor welder to turn the generator. It worked pretty good.
Harv any chance you want to sell your 3 phase plasma cutter. I was gonna buy one from the trailer plant i worked for but they closed the other day and one of the clean up crew rolled it off the storage balcony to avoid having to lower it with a forklift. Thanks for the information fellas my Welders Supply here is a little parts house and the owners never has even attepmted to weld. They think since they dont have 3 phase that i dont so there a bit one sided.

 

[JohnMiller3]

Hi Taylor,

You may want to investigate the “minimum” monthly costs related to having 3-phase brought to your building first… then after it’s established find out the minimum billing cycle your utility company will keep you on it… /w3tcompact/icons/blush.gif /w3tcompact/icons/eyes.gif

Here in NY, we had it in an old factory building my Father had purchased… we couldn’t shake the 3-phase minimum billing for something like 24 months and then the “kw rate” remained high for like 36 months (don’t hold me to the exact periods/rates as this occurred in the early 80’s when electric rates were actually cheaper than today)

This was a legal method for the utility company to gouge the customer, is the best way I can put it… /w3tcompact/icons/sad.gif

If you went 3-phase… it may be cheaper for you to “buy” your buddies their own equipment versus your planned work-around solution… /w3tcompact/icons/shocked.gif

 

[Taylortractornut]

Well i actually own alot of 3 phase equipment, I own a 15 horse lathe with a 30 inch swing, a 6 foot swing 5 Radial arm drill and 5 horse metal plane and a 4 horse Sheetmetal shear. I still have to buy a mill, surface grinder and a Quorn rotary tool grinder. I was using a 3phase converter but they get very hot and is something ese to fail. I do pay 2 dollars a month more service charge. Its hard to find and sometimes convert every thing over to 220, Being alot of machins have special motor casings and seals. Plus most 3 phase machinery is cheaper to buy and operate.

 

[chim]

We have different plasma cutters at work, but the only one I'm familiar with is what we call the "suitcase plasma". I've seen our guys do some serious stainless cutting with that 110v model. Without further exposure to the world of plasma cutters, it seemed to me you'd need to be doing salvage work on an old battleship to need one that required a 3 phase hookup.

I assume there would be some advantage to keeping your load balanced on the electrical service, but not knowing what it takes to run the plasma cutter kinda makes it hard to quantify. The current could be so low that mixed in with your other loads it's inconsequential.

There's also a general misunderstanding over just how much can be gained financially by using 240v vs. 120v or 3 phase vs. single phase to run equipment. There usually is an efficiency gain, but you buy power, not amps. It takes power to run machines. Power is what you pay for, although some utilities penalize you if your power factor is poor. This is the result of inductive loads. Anyhoo, you'll get the same bill for running a 10A load on 120v single phase as you would for a 5A load at 240v single phase.........................chim

 

[Anonymous Poster]

The savings in 3 phase as opposed to single phase come 3 ways.
First, a 5hp 3 phase motor draws less amps per phase, so smaller wires & conduit service the same horsepower.
Second, Amps drawn are divided by 3, this becomes a major consideration if you are paying demand charges.
Third, there is a lot of surplus 3 phase equipment available in the used marketplace.
You can also employ larger motors on 3 phase than you can on single phase.