Airforce 400 Wiring (where is the Sparky?)

[HT1]

I have an Airforce 400, there is absolutely no chance of running it on a dedicated 115VAC recepticle, it trips the breaker every 8 seconds, cutting is like a rodeo. So I went to replug it to find that all the working recepticles in the building are 3Ø, 230. and 440. so I called the electrician and asked him if we could just pull two legs from a 460 Ø recepticle. he stuttered a bit, and said he was not sure... He is new, and I'm almost posative that is how most of my equipment is wired...

Any help?

Thanks in advance

[hankj]

No, you can't just "pull" any legs off of any other receps.

Thr right way to do the job is to pull a new 20A, 120V circuit from the panel. Is the breaker that you keep tripping on the circuit you use a 15A or a 20A? Is your receptacle the only on served by that breaker?

Typically, 15A circuits are lighting circuits fed with #14 copper, and they don't usually have recptacles on them. My guess is the circuit you are using is a 20A convenience outlet circuit, and there are more outlets on it than the one you are plugged into. If you can eliminate (unplug) the loads on the other recep's supplied, things may work out.

Hank

[Broccoli1]

Hank,

I bet that 400 is useless on 20 amp 120v

"A 30 ampere branch circuit is recommended for maximum performance. Performance on a 20 ampere branch service may be limited due to the circuit
breaker or line fuse. Reducing unit output amperage will minimize circuit breaker tripping or blowing a line fuse."

[MAC702]

If this is an industrial setting (assuming it is based on avail. 230/460V 3-phase power) it's usually a very quick job to pull a proper dedicated circuit from the panel. Figure out where you want the machine and just install a 30A dedicated circuit to it, just as was done with all the other equipment in the shop when they were installed.

[HT1]

obviously i did not make my question clear. I have no intention off adding any 115VAC recepticles. every115VAC recepticle in the building is a 30A though none are dedicated. if I add a recepticle it will be a 208-230VAC it is that simple. I would have to install several HUNDRED feet of conduit to get the dedicated circuit to the location where I will need it.. My intentions where to take a hubbel 460VAC (sorry im at home, and do not have the model number available to me) twistlock plug, and attach it to the plasma cutter, and only attach two hot leads, and the ground. there is not a 4th wire from the plasma cutter anyhow. i was told, this would give me 208VAC single phase. I'm concerned that the plasma cutter may not like that power since it specifically asks for 230 VAC. any commentS

[MAC702]

Two hot leads on a 3-phase 460V receptacle/plug will still give you 460V, only at single-phase instead of three-phase. You would need to rewire the receptacle-to-panel with a neutral (possibly just converting one of the existing hot wires into a neutral with appropriate recolor-coding) and now you are looking at a possibility for 230V power. You will need to read your owner's manual to determine if your machine will tolerate 230V-240V power.

Several hundred feet of conduit and wire is a typical installation in an industrial setting. It's not often that someone in this setting is looking for the cheap way out. But if you don't need one of the existing 460V receptacles, you MIGHT be able to rewire it as described. It depends on what kind of 460V panel you have.

Never underestimate the value of a licensed electrician performing the job.

[HT1]

Two hot leads on a 3-phase 460V receptacle/plug will still give you 460V, only at single-phase instead of three-phase.

if what you say is true, i can connect the ground, X & Z pole on the plug, and that would give me 250 VAC single Ø







as far as the cheap way out, I only need this to work for a month, a new Miller Plasma cutter is on order, the Hobart is our "emergency" unit. always test the emergency backup extensively!!! the Pakmaster got soaked when a window broke during Tropicl storm Fey... but I've been putting off work, and the boss is getting angry... I will be cutting aluminum with a hack saw soon.

[Sberry]

He says he has 230 3 ph, cant we get 208 from this?

[hankj]

if what you say is true, i can connect the ground, X & Z pole on the plug, and that would give me 250 VAC single Ø







as far as the cheap way out, I only need this to work for a month, a new Miller Plasma cutter is on order, the Hobart is our "emergency" unit. always test the emergency backup extensively!!! the Pakmaster got soaked when a window broke during Tropicl storm Fey... but I've been putting off work, and the boss is getting angry... I will be cutting aluminum with a hack saw soon.

NO!

If, as Mac said, the outlet is 3-phase 460VAC, you will get single phase 460VAC from two hot legs. Same thing from two legs of a 3-phase 240VAC circuit - still 240VAC, but only one phase.

The picture you posted shows a NEMA confoguration that is rated at 250VAC. Connecting it to a 460VAC circuit will still give you 460VAC!

There is no viable option for getting 120VAC single phase power from any 3-wire multi-phase outlet. If you have 4-wires, you could get 120VAC from a hot leg and the neutral of a 3-phase 240VAC circuit if it is configured correctly.

Hank

[Broccoli1]

Same thing from two legs of a 3-phase 240VAC circuit - still 240VAC, but only one phase.

hank,

I think this is exactly what he wants to do. No 120v involved.

The 400 can be run on either 120v or 240v- single phase.

He wants to run it on 240v using 2 legs off of the 240v 3-phase outlet.

[HT1]

hank,

I think this is exactly what he wants to do. No 120v involved.

The 400 can be run on either 120v or 240v- single phase.

He wants to run it on 240v using 2 legs off of the 240v 3-phase outlet.

This is exactly correct!!! Will it work?

[hankj]

Yes, it will. You may only get 208V, but the 400 will run OK on that. It depends wether your 3-phase is Y wye or delta wired what you'll get, but it oughtta work OK fer ya.

Hank

[Terry Lingle]

If I read this thread correctly the supply is 460 VAC That could be a delta connection or a star connection ,
If it is a star connection the voltage will be 277 line to neutral This may not be to healthy for the machine

If it is a delta connection that has the center tap of one leg grounded then 2 of the three legs will give 230 v to ground but the third leg will be something like 330 VAc ( it's known as the wild leg) and will destroy the machine .
This system would be a very old system but they still exist.

You need to know what the supply connection is before you connect the machine up to it.

If it is a simple three wire delta 460 volt system there is no way short of a transformer to run a 230 volt machine on that system.

[HT1]

This is a full blown industrial setting, in a building built in the early 70's, and upgraded several times. Thus why we have so many different powers in the building 460, and 230 bot, now unfortunately the "company" has an electrician on staff... So getting someone more knowledgable here, would probably require getting him fired. I'm going to "borrow" a meter, get the best power I can for the machione, and wire it up. if it fries it... I will send pretty pics of the flames.. if it works, i will let everyone know what I did....


On a strange note, I have located a 230 single phase recepticle in the building, but it is in the most out of the way place, and according to the electrician, it is not giving proper power.... glancing over his shoulder, I saw 208VAC I'm going to just plug the machine into it, and if it gives an acceptable performance. I will make up a VERY long extension cord... and hope I do not loose too much from that!

[Thurman]

Airforce 400 wiring

I'm sure I'll be corrected if I'm wrong here but: When taking two legs and ground off of a four wire 440V/3 phase circuit won't that give you 277 volts/3 phase? Thanks, David.