Circuit Amps

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If my wall circuit is on a 50amp GFCI breaker...that's not enough to weld is it?  Do I have to install like a 200amp breaker and the appropriate wiring?
Reply:Huh? Most transformer based stick machines will draw a max of roughly 50 amps 230v. You can get by with them on a 30 amp 230v circuit if you stick to 3/32" rods or less.  Big industrial transformer machines might draw as much as 125 amps 230v, but when they do that they would be putting out like 400 amps output.Not sure about the GFCI part. I've never tried to power a welder from one. All my welders are on standard circuit breakers not GFCI's..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:A bit more information is going to be needed. First, if this is an already wired circuit, was it done for something like a hot tub or other heavy amp load? What wiring gauge is used on the circuit? What sort/ type/ size/ whatever welder are you asking about? To give you a general answer...a 50 amp circuit should be fine for most medium to large sized MIG welders, a good many medium sized inverter TIG welders and enough for maybe 2/3rds output on traditional transformer based stick welders IF AND ONLY IF the wiring matches the breaker's output. There is a wire size derating to the N.E.C. code due to the fact that welders are classified as intermittant usage/demand machines unlike electric motors and heaters. Go check the wire gauge and come back here with the size and also information on what welder you are interested in running on this circuit and you can get a definitive answer.Lincoln PrecisionTig 275Miller 251Miller DialArc 250Bridgeport millHossfeld bender & diesLogan shaperJet 14 X 40 latheSouth Bend 9" 'C'Hypertherm 900Ellis 3000 band saw21"Royersford ExcelsiorTwo shops, still too many tools.
Reply:Just not enough information to tell you much of anything at this point.  Repost your request with something useful like the make and model of welder, the manufacturers requirements for input power (found in owners manual) and intended use of such machine.I am running a Miller Dial Arc 250HF on a 50 amp circuit and it welds away happily up to a point then it trips the breaker.  The manufacturers recommended input power is a 100 amp circuit for the full usage of 300 amps output.  Since I don't really ever get anywhere close to the maximum power output requirements the 50 amp circuit works quite nicely and the one time I did wail on heavy aluminum was just for fun.RogerOld, Tired, and GRUMPYSalesman will call, Batteries not included, Assembly is required, and FREE ADVICE IS WORTH EXACTLY WHAT YOU PAY FOR IT!Dial Arc 250HFThunderbolt 225 AC/DCAssorted A/O torches
Reply:Another important piece of the puzzle is how long the wiring is.  The longer the cord the more resistance in the circuit which means a higher current for the same power at the receptacle.  A good electrician will go for the heavier gauge wire if the distance becomes too great.  Offhand I'd say it becomes important past 50 - 100'.  At my place I have a 240v plug about 500' from my panel so I had to run heavier duty wire than what you would think.GFCI shouldn't matter unless you have an earth-ground somewhere in your worksite.  All of my outlets outside are GFCI so I don't have a choice if I'm welding outside.  Up in the shed is a different story as it is inside.
Reply:I think the poster is mistaking power supply amps and welding amps. The welder steps down the voltage from 240 (120) to around 30 to 45 volts and at the same time ups the amps by the same ratio. So a 50 amp supply would  give over 200 amps at welding voltage.
Reply:Originally Posted by mwshawI think the poster is mistaking power supply amps and welding amps. The welder steps down the voltage from 240 (120) to around 30 to 45 volts and at the same time ups the amps by the same ratio. So a 50 amp supply would  give over 200 amps at welding voltage.