putting in plug for welder

MESSMAKER · Aug 3, 2011

I need a plug in the garage for my 220 welder. I was hoping to share the 220 coming in for the water heater. The first problem is, how to get around the WH coming on while I am welding and overloading the circuit.I am thinking that I run hot to the welding plug then branch off with a switch on the line to the water heater, so i can just turn it off when I am welding. I just have to remember to turn the power back on.
The second problem is that I have a nice HD extension cord that I use with my generator. It has both 110 and a 220 welding plug on one end. It has a four prong twist lock on the male end. Can I wire up a box that will fit with the 220 wire that I have which just has a red, black and a ground( WH wire). I am a little fuzzy on the neutral on the 4 way. I think I just cap off the neutral and go from there. I would have a working 220 plug, but my 110 plugs will not work, which I am OK with.

mjncad · Aug 4, 2011

Please run a new circuit for your welder.

schmism · Aug 4, 2011

If i remember my NEC section on 220 wireing....

there is only one exception for mulitpul devices (outlets) on the same circuit and its for a garage welder or other tool. were the shop only has one and you never expect both outlets to have a tool in them at the same time (ie the welder is either at A or B but never at both)

for all other 220v circuits im fairly shure your not allowed more than one device on it. ie you need a dedicated run to the welder or other 220v device.

Monster5601 · Aug 4, 2011

I chose to have a sub-panel installed in the garage. It cost me $400 to have an electrician install it but it is well worth the cost.

MESSMAKER · Aug 4, 2011

I do woodworking and already have a sub-panel, but it is full of 110 circuits. The only way I can use it is to replace the reg. breakers with the skinny type so I could free up some space. I was also told that I could mount a receptacle on the 220 and a welding plug on the wire running to the water heater. That way I could just unplug the waterheater, leaving a free receptacle. I have seen several people do this with a clothes dryer that was located in the garage. This would force me to make a dedicated extension cord, I think.

ducks13 · Aug 4, 2011

You have a plug or switch on your water heater? That would be unusual. You will meet code if you always turn off the water heater before using the welder. Tuning the thermostat down low when you start welding would work but you shouldn't be welding if the water temperature is low enough for it to come on.

oldnslo · Aug 4, 2011

Messmaker,
what size breaker feeds your water heater today? Is it large enough to run your welder. Just curious because my water heater is 30 amp and welder is 50 amp.

yomax4 · Aug 4, 2011

I'm not sure what size welder you want to run but I doubt that the water heater line is more than 10 ga. You will probably need 8 or 6 ga. Also I am unsure what happens when you put a 20-30 amp water heater on a 40-50 amp breaker.

deereman75 · Aug 4, 2011

I have a 30 amp power in the laundry room, and when I need to weld, I un plug the dryer, and hook up the 25 foot, 4 gauge cord. My welder is a lincoln ac 225, and draws 50 amps at max power, but since I only have 30 amp power, I just dont turn it up beyond 160 amps or so, so it only draws up to 30 amps.

MESSMAKER · Aug 4, 2011

deereman75 said:
I have a 30 amp power in the laundry room, and when I need to weld, I un plug the dryer, and hook up the 25 foot, 4 gauge cord. My welder is a lincoln ac 225, and draws 50 amps at max power, but since I only have 30 amp power, I just dont turn it up beyond 160 amps or so, so it only draws up to 30 amps.

I am in the same boat. I could run a wire to the dryer plug, but that would be a PITA. The wire for the water heater comes from the main box and hooks into the heater about 24" from my sub panel. Is there a difference between an unplugged or switched off dryer and a water heater. The fact that the dryer usually has a plug and the water heater does not is all I see. I have seen several dryers hard wired for that matter. The welder I have is a med. sized mig and pulls less than 25 amps.

deereman75 · Aug 4, 2011

We had actually payed for 20 feet of 8 gauge cord, and the new guy at the cable dealer got us 25 feet of 4 gauge, and it only cost us like $50. We actually have to have the cord running through the basement, to the garage right now, but we will be setting it up with its own circut soon.

Travelover · Aug 4, 2011

At my local scrap yard they have piles of large gauge THHN wire that are new, but off the end of a huge roll. I bought some 25 foot pieces and made my own welder extension cord. I don't recall the gauge, now - be sure to check before you buy.

Bobby R · Aug 4, 2011

The best and safest way is to install a "piggy back" breaker box next to your existing one, and run a new line for your welding machine with the proper size wire and plug so it will be on a circuit of it's own. That's what I did and I haven't regretted it for a minute.

MESSMAKER · Aug 4, 2011

I may look into that. My main box is 75' away so that will be $$ in materials.

Bobby R · Aug 4, 2011

Yeah, you're right. The heavy wire required to carry a welding machine and the distance you've got to run it will cost you, but once you've done it, you won't have to worry about it. At least that's the way I looked at it. I had to run about 35 feet of wire from my piggy back to where I wanted my welding receptacle.

mjncad · Aug 5, 2011

Doing it right is cheaper than doing it wrong and burning your house down.

MESSMAKER · Aug 5, 2011

mjncad said:
Doing it right is cheaper than doing it wrong and burning your house down.

I am not sure how that helps me.

I could build a new metal building with a concrete floor with a moat around it and get fire suppression system installed. I am looking for options and pitfalls. The crux of my question involved getting my welder on the end of a proper ex. cord that I already own and use with the welder.This would allow me to use the welder in a safe spot. I thought this might keep me from BURNING MY HOUSE DOWN.

I don't mind being warned of a danger of a specific action, but telling me that "The sky is falling" really does not tell me much.

rjmack · Aug 5, 2011

I'm not sure what size welder you want to run but I doubt that the water heater line is more than 10 ga. You will probably need 8 or 6 ga. Also I am unsure what happens when you put a 20-30 amp water heater on a 40-50 amp breaker.

i'm NOT an electrician.

the water heater is probably 12 or 14 gauge, not even close to big enough. and the breaker is probably a 10 or 15 amp 240v 2 pole.

the basic bottom line is that the whole system, from the main breaker on your main distribution panel, cannot 'step up'. if your water heater breaker is 15 amp 240v, then that is all you will get from that circuit... if your dryer plug is 30 amp 240v, then that is all you will get.

i know from experience that you can run a miller 252 plenty hot on a 30 amp 240v circuit... going to a 10 or 15 amp sounds a little dicey.

btw, the power at my place runs about 117-118v/234-236v. the distance from the pole to the main panel is about 100'.

ampacity and voltage drop charts are readily available online, that's probably where you should be looking.

i'm assuming you have a meter to measure actual voltage on your system? voltage drop is an important factor.

how to get 120v AND 240v from the same breaker without a sub panel to split the 240v through a single pole breaker is beyond my knowledge.

for all other 220v circuits im fairly shure your not allowed more than one device on it. ie you need a dedicated run to the welder or other 220v device.

i have 2 240v plugs running from the same feed, one runs the plasma cutter/welder, the other is for the compressor. they will run at the same time. i imagine the welder turned up all the way and welding while the compressor is running might trip the breaker, but it hasn't happened yet. either way, the wire is heavier rated than the breaker and the voltage drop is within the specified range, so i'm not worried about it.

mjncad · Aug 6, 2011

Sorry for the general tone of my replies as I figure you're smart enough to find out the proper way for your location. Lots of local governments love to monkey with national codes as a revenue generator.

I don't mind local code enhancements for legitimate reasons (e.g. earthquake or hurricane zones); but it pisses me off when they do it to make a buck.