What's needed to wire up a rotary 3ph converter?

Rotary converter will be installed in my garage and used to run lathe & mill (one at a time). Supply will be dryer circuit of 30A 220v.
Wiring up is straightforward, but what switch(es) and fuses should I use?
The converter no switch or fusing. The lathe and mill do not have fusing either.
Is the 30A breaker sufficient to protect the entire setup? Is one 2-pole disconnect knife switch (with 20A fuses) sufficient to protect all?
Suggestions?
Thanks.
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On 4/9/2011 10:43 AM, Paul Conners wrote:

Not sure how your phase converter is setup up, but I strongly suggest you make sure it won't start back up on its own in the event of a power failure and return to power. Could be very dangerous. Make sure you ALWAYS have to manually start the phase converter.
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I agree, use an electric contactor instead of just a manual switch. Set it with a START/STOP set up.
You sould expect about 180 amps starting current.
i
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Overvoltage?
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wrote:

You are truly a numbskull, Gunner.
Since, surprisingly, your house hasn't ( yet ) caught fire...

Zoom....
Hmmm...
In the case of my installation, the OUTPUT side is into a 20 circuit 3ph breaker panel and if I were to put a 30 amp fuse there at the output it would barely allow even running the air compressor let alone the rest of the machines that are wired onto the buss...
--FWIW the input side is a 125 amp breaker which feeds single phase to the idler which is a 50 hp Toshiba Hi E
BTW, whoever it was here that mentioned using a contactor and definate start /stop circuit to forbid auto-restart upon power fail or brown-out is spot-on..
--You definately want the magnetics to drop input power altogether in this instance otherwise you will get huge HV transients sent down the line--not good if you have any computers or equipment that uses varisters to protect against spikes.
--




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Gunner can count them on his fingers and toes at customer sites. Lots of them in his work area.
I got one from him and have it running in my shop on 220 and 3PHase contactors. I have some 220 contactors if anyone needs one or two.
Martin
On 4/10/2011 1:26 AM, PrecisionmachinisT wrote:

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Most of them are out of business now....
Hiring him probably was a major contributing factor.

--



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ELI the ICE man.
Voltage leads current in Inductive Current leads voltage in Capacitive circuits.
Rotaries are inductive. Motors are inductive. The rotary is somewhat balanced over a range. But motors are not.
Starting and stopping motors causes surges and spikes. The impedance quells some of that and enhances others.
Martin
On 4/9/2011 8:24 PM, Ignoramus28444 wrote:

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typed in rec.crafts.metalworking the following:

    Just for your amusement. Friend reports that one of the main machines is down at work. It had been acting up, errors in Z, and last week - it tripped the breaker. Somehow, he didn't know, and I couldn't follow the explanation on possible causes (out of my area of understanding.)     1400 amp, 3 phase, 430 volt service. tripped the breaker. "Ooops".
    Good news - with that machine down, he can get Holy Week off.
    Worse news, the supply factory for the inserts for the 2 inch face mill which does the majority of their work - is dun got washed away. So, they have about a week's supply on hand and then .... they do not even have enough on hand to cover wheel they scramble for a replacement.
tschus pyotr
--
pyotr filipivich
We will drink no whiskey before its nine.
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on Sat, 09 Apr 2011 15:28:52 -0700

1400 amp at 430 ( 430 ? ) is enough to power a small city here where I live in rural Wa State
I have never encountered a machine tool that uses that much power but for academic purposes let's just run the numbers....
1400 x 430 = 602,000 kva ( WATTS at PF 1 )
= 4,289.4 horsepower....

Well, since it's unlikely they can afford the power bill anyways...

Sounds to me like the place is run by total idiots--and it's readily apparent that you would probably fit in very well there.
--



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This video shows at slow speed how hex cutting is achieved:
<
http://www.youtube.com/watch?v=-9jMN9Bgg6g&NR=1

Dave
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pyotr filipivich wrote:

The breaker is a GFI breaker and is tripping on a short to ground on the machine, not necessarily drawing a lot of amps but on the unbalanced flow of current.
John
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in rec.crafts.metalworking the following:

    Okay. He said that they don't have Ground Fault Interrupts on that setup, but ... who am I to say?
--
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pyotr filipivich wrote:

I believe that on newer 480 service disconnects Ground Fault interrupts are required over a certain amperage. Newer would be in the last fifteen years or so.
John
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in rec.crafts.metalworking the following:

    I'll ask when I see him next.

--
pyotr filipivich
We will drink no whiskey before its nine.
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Yes -
I have one in my shop - generates 3-phase (one a little wild) and then I step up the 220 to 380v and send it to my grinders.
I have a circuit - you can look at mine and strip down.
I have circuit breakers and contactors I have a box that holds them - pro grade - and a hand plug that plugs into my 220 plug in the shop. (I have a 30x30 building) From the box I have 22o on a second local breaker - and a contactor that switches 220 to the rotary. Rotary comes back through a breaker to a contactor and then to distribution sockets.
I have extension cords on mine - 3 phase ones - but some want to wire and use more often than I. My grinders are 1% use. Want to get rid of one.
If you want the design - I might be able to find it - and send you a copy.
Martin
On 4/9/2011 12:43 PM, Paul Conners wrote:

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