transformers

Hello I am a new member here and i have a quick question. I am a machinist but i now nothing about electricity. i am in the process of buying a hass toolroom mill tm-1 and it is asking for 208 volt @25 amp

3 phase 9kva. is there a transformer i can get to hook it up to 240 volt single phase in a house? also how many amps will this draw from the 240 volt? i am in ontario canada and all i have coming to my house is 120 volt and 240 volt. i will be building a new house in 1 1/2 yrs and when i get hydro to connect me i will be asking for the proper service. but up till then this is all i have to work with. any help would be great

Robert Ouellette

If you're not willing to replace the motor(s), then you'll probably need two transformers and a rotary phase converter to do what you need.

The transformerS, surprisingly, won't be expensive. Instead of the traditional primary/secondary relationship, with a secondary rated at the full load current, you can use inexpensive "bucking" autoformers to drop each 120v leg to 104v.

Doing this with only a single, unbalanced autoformer leads to problems, like the two legs won't be balanced to neutral.

Once you have single-phase 208v, you convert that to 3ph with a rotary converter (rated at 208v).

This is not an inexpensive solution to your problem, unless you're willing to build your own RPC. The transformers will cost you probably less than $100 each if you hunt a bit.

LLoyd

You'll need a phase converter or a VFD. Getting 3 phase to your house is going to be pricey. Where in Ontario are you? Windsor by chance?

If you know nothing about electricity, please hire someone that does. No insult intended, it's just the prudent course. I'll bet you don't do your own dentistry!

Thanks for the quick replies. how much are load on the house panel am i looking at? how much is a phase converter?

I live near Cornwall Robert Ouellette

Just get a VFD, it will do what you need (drop 240 to 208 and convert single phase to 3 phase).

i

No...a transformer will not give you 3ph power. However a "rotary phase converter" will do so. They are available commercially or fairly easily built by yourself.

Ebay has many commercial ones available

Do NOT purchase a "static converter"

If the Haas is new...ask them about the warranty issues of running off a proper Commercial phase converter. Some manufactures are bitchy about running them off home made units and play games with the warranty. I repair machine tools for a living..and while I dont work on Haas..I know a number of folks who do..and the RPC issue has come up before.

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

I think the mill referenced is a small CNC mill (didn't look it up). I don't think a VFD would be very happy feeding such a load.

Pete C.

At 120/208V three phase the mill is pulling 25A per phase so three phases are 75A, divide that total by the two phases you have (120/240V single phase) add something in for phase converter losses and you're looking at a good 50A 240V single phase circuit to supply the converter and mill.

A rotary phase converter of the size you need commercially purchased will cost thousands. If you can scrounge parts and build one yourself (they aren't very complicated) you could probably build one for well under $1k US or equiv.

Pete C.

The Haas toolroom mill is a full blown CNC mill. Its quite picky about input power.

Its not something one can get away with doing a Mickey Mouse on.

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Wont work in this application...

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

It wont. The VFD or the mills control or drives will puke in very short order.

An RPC is the only way to operate it.

The original poster should also join the alt.machines.cnc newsgroup. A number of Haas users over there

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

The Haas toolroom mill is a full blown CNC mill. Its quite picky about input power.

Its not something one can get away with doing a Mickey Mouse on.

However..reading the blurb above..it says the mill may be run on single phase. A nice touch..and within the need perameters of the intended end user.

"The TM-1 operates on either single- or three-phase power. The 7.5 hp,

40-taper spindle spins to 4000 rpm. A one-piece cast-iron base/column damps vibration and provides rigidity for heavy cuts. An optional 10-pocket tool changer is available for faster cycle times and automatic operation"

So it may be a moot consideration if his can run on single phase. It will likely be happy on 240 volts, or a simple buckboost transformer will work.

First thing Id do, is call Haas tech support. Or the local Haas dealer he bought it from, if it will have a warranty attached.

Gunner

Political Correctness

A doctrine fostered by a delusional, illogical liberal minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a turd by the clean end.

Gentlemen, you are right and I am wrong.

i

Thanks all who have replied. I did notice the single phase refernce but as i said i am a machinist not an electricain. i have a call into haas asking about it and am waiting for a reply. and yes it will be a new machine so i do not want to mickey mouse it. and as for the cnc group i have been lurking for a very long time and have even posted a few but it has been a little while since i have been on here seeing as i anly have dial up i find it way to slow for me. thanks

Robert Ouellette

I'd recommend you contact haas about this one...

I'm looking through the HAAS website, downloading the Manual Addendum, and it wants either 208V 3Ph or 240V 1Ph, 50 or 60 Hz, 40 Amps, with a good ground. Most houses can pull this off. Worst case, the Clothes Dryer circuit can be disconnected, and you stick the 40A mill breaker there. For Single Phase you feed L1 and L3, and it sure looks like it has an internal VFD.

If you've never done this before, call an electrician. Note that there are two jumpers on the internal control transformers that have to be swapped for 208V or 240V operation. You really want to get these right BEFORE turning on the power.

Voltage Imbalance under 2% - this one your utility might have to address if there are bad connections on the feeder, or they have the loads way imbalanced between the houses on the transformer.

THD under 10% - For residences, not a problem. Where this is an issue is office buildings with tons of computers (switching power supplies), and industrial buildings with lots of power tools.

One other thought - If you're getting this new you might want the fully enclosed TM-1P. Flying coolant and swarf going everywhere is fine in an industrial setting, but in a home shop every bit of swarf is going to stick to clothes and shoes, get tracked inside, and deposited in the carpets. This will NOT endear you with SWMBO.

And at industrial shops people know better than to stick their hands where they don't belong. But at home, the resident cat/dog/child is liable to take great interest in what the mill is doing while it's running and you are away for a moment, leading to Huge Vet or Doctor Bills. With the full guards they can get smacked with the table as it traverses, but the cutting tools are safely surrounded.

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