Welding Tips and Tricks

I have an Mtn Gearsmith cut-50DX plasma cutter that I am hoping to have setup in a shop I am leasing. Here is the question:

I have 30amp 220V service that was just installed at my cost but see that this machine refers to 50amp on 220V....do I need to get additional electrical service installed to run this cutter? It reads that it can run either 110V or 220V but I haven't seen anybody refer to having to add new electrical service to run these....does anybody know what is needed?

As always, thanks in advance for any advice, comments, or food for thought on this

thanks

Hard to imagine a small plasma pull 50amps....
I had one and I ran it of a 20amp....
Try it, and see if it blows the breaker, simple test.

Hi - your plasma cutter should run just fine on 30amps input - the typical import inverter cutters generally run around 100 volts while cutting - they are quite efficient & will draw on 220 / 240 volts about half what the cutting current is ( 50amps in your case ) so I would not expect the unit to run more than about 25 amps input - there seems to be wide spread confusion with plasma cutters - but almost always the current stated or in the model number will be the cutting current - not the input - with a dual voltage machine they draw nearly the same amps on input as cut on 110 volt - hence machines like yours are restricted when used on 110 - I believe 30amps cut is the max for yours & around the same from the mains supply - usually on the back of the machine there should be a silver / black tag with this information printed on.
Hope that helps.

I would keep it on 220.
I had a machine very similer to yours and on 110, and it said same output on 110 and 220.
But it couldn't cut sheet metal on 110, I wired it up 220 and it will blast through 1/2 steel. machine like cut.
Keep it on 220, 30amp breaker, and your n bussness....
Let us know how it works.

~John

I have a small machine that runs either 110 or 220 and I have it hooked to 110 right now and I am currently wiring up a 220 outlet for our shop so I can bump it up. On 110, my machine won't run at full amps so I would keep that in mind.

My machine would run up to 50amps on 110 and 220.
Noooo way...
That piece of junk died after ten uses!!!
Piece of S***
Here's a saying (thanks Willie B)
When a guy buys a high quality and durable unit, He doesn't say, "Man, I wish I'd of bought some cheap piece of garbage"!!!!
Never.

IMVHO

~John

That 30A/220v circuit is probably a standard 220v circut that is 15A/110v per leg and is most likely wired with 14 ga wire, certainly not heavy enough for cutting/welding and would likely melt the wire at max draw at 50A, remember that 110v welders/cutters reuire a 20A circut with 12 ga wire, so you're probably under capacity to start. You're going to have to replace the wire in the circuit with a minimum of 8 ga wire (6ga is better) to handle the max load as well as a 50A breaker. Probably makes most sense to add a dedicated circuit for the cutter as you'll be replacing the wire, the circut breaker and the receptacle. If this space is insured (business or hobby) you will have to make sure all your wiring can handle the intended loads based on the local electrical code. If your circuit not up to code you're creating a loophole that your insurance company will use to crawl out of paying you a dime for your own negligence. If you're not comfortable with electricity the best bet is to get an electrician in to assess and install the necessary provisions, sure is cheaper than replacing a burned down house.

RhatterNTatter,

The "50 Amp" is cutting current, not "input current", just as noddybrian said. An analysis (as was given, but with formulas):

Let's assume the cutting voltage is exactly 100V, for simplicity's sake. Then, cutting at 50A current is a 5000 Watt power consumption at the torch. (Power = current X voltage). To translate that into input current from a 220V source (again, for simplicity, I'll assume a perfect, no-loss system), you get about 22.75 Amps (Current = Power / Voltage) drawn at the plug. Allowing for losses to heat, cooling fans, control circuits, and the inherent inefficiency of a "real-world" machine, you are still under 25A draw to run the machine wide open.

Additionally, I have heard (but not researched or verified) that dual-voltage machines like yours use a lower cutting voltage, as low as 80V, to reduce the current draw for a 110v 20A circuit, and would also reduce draw at 220v.

You are in no danger of overloading your circuit, and the breakers will protect you if you do. Despite one comment, your new 220 outlet, done to electrical code, will have at least 12 ga. wire within 25' of the box, and 10 ga to 50' (or maybe 75'... I'd have to review the current code and sizing charts).

Go burn some steel!

Steve S

The manufacturers rating label that's probably on the back of the machine should list what is needed for the primary voltage in regards to rated maximum supply current and maximum effective supply current.

by bearston » Fri Jun 20, 2014 9:11 am

That 30A/220v circuit is probably a standard 220v circut that is 15A/110v per leg and is most likely wired with 14 ga wire, certainly not heavy enough for cutting/welding and would likely melt the wire at max draw at 50A, remember that 110v welders/cutters reuire a 20A circut with 12 ga wire, so you're probably under capacity to start. You're going to have to replace the wire in the circuit with a minimum of 8 ga wire (6ga is better) to handle the max load as well as a 50A breaker. Probably makes most sense to add a dedicated circuit for the cutter as you'll be replacing the wire, the circut breaker and the receptacle. If this space is insured (business or hobby) you will have to make sure all your wiring can handle the intended loads based on the local electrical code. If your circuit not up to code you're creating a loophole that your insurance company will use to crawl out of paying you a dime for your own negligence. If you're not comfortable with electricity the best bet is to get an electrician in to assess and install the necessary provisions, sure is cheaper than replacing a burned down house.




Bearston,if this guy payed somone to install a 30a service and they used 14ga wire to do it then he should have the guy replace that service due to not following NEC codes. 30A requires at LEAST 10ga or larger wire to start,per NEC. the only thig that should have any 15a wired with 14ga would maybe be a couple of lights and even that is against code due to reqiring min of 20a circuits in garages and such. Like the others said you should be fine running your machine on 220-240vac the draw wont be enough to trip a double pole 30a dreaker unles you have a short in your machine.