Electrical question - garage welder

[cashflyer]

I know there is at least one electrician on this board who will have the answer....

My Miller welder has a three prong plug. 220v
Looks like this:


Prior to the remodel, the old receptacle had the red, black, and white.
When they pulled the lines during the shop remodeling in 2011, the electrician told me that code now requires all 220v circuits to have 4 wires - 2 hot, 1 neutral, and 1 ground. So now I have a red, a black, a white, and a bare copper wire.

How do I wire a receptacle that my welder will plug into?

Or am I stuck buying a 4-wire receptacle AND a $50 adapter pigtail like this?

[pete3799]

I'm interested in the answer to this as well.
One of my generators (welder/generator)has a 3 prong plug and the other a 4 prong.

[jyl]

How to Convert 3 Prong Dryer Cord to 4 Prong | Home Guides | SF Gate

Maybe this helps? I don't know the answer but was curious enough to look. I was not aware 220v outlets had to be three prong now. Is that only in inhabited spaces? Does it apply to garages?

[Charles Freeborn]

Interesting... I've never heard of 220v single phase power using 4 leads... only 3 phase.
I would imagine that you could determine which poles are what with a meter (using voltage test) from each hot leg to ground and then wire your receptacle accordingly. 220 has 2 hot (110 each) and one neutral (usually the white lead). The fourth must be an independent leg to the unshielded ground. The neutral and ground both go to a ground bus inside the breaker panel. Just my guess, as I haven't done a code required job in a while.
-C

[GWN7]

Three choices. 1) Buy a old style plug that fits your welder cord and replace the current up to code plug with the old style plug. The cost of this will be about the same as buying a adapter cord to fit. The down side to rewiring not to code is that if you have a problem with your house is your insurance company can refuse any and all claims you might make. 2) Buy a new male end for your welder cord to fit the new wall plug. Cost will be about the same as the adaptor cord. 3) Buy the adaptor cord.

[dyount]

The ground (bare or labeled green) is in this case an equipment grounding conductor. Step 1 check to see if somewhere in the connections of your welder pigtail you've got a spot to attach a ground to the metal parts of the welder? should be able to find. As well, with the age of your welder the cord is probably not in the best condition age wise at this point and can be replaced.
Step 2 if cord cannot be grounded to the welder I'd use a UL listed (non home made) transition cord if you have to.
History on this basic subject including dryers/ovens is that although a grounded conductor (the neutral) was present the frame of the appliance could become energized so a grounding conductor was added to the NEC.
In my opinion if the welder and it's current cord are in good condition I'd have no problem approving the newly installed receptacle with 4 and a transition to 3 if it's done with a listed transition plug.
Not an electrician but rather a International Code Council certified Master Code Professional

[rick-l]

Hey code guy.

Is that a NEMA 6-50 plug on his welder? I think the round, long prong is always a safety ground, is that correct?

Does this mean that no current should flow in this wire during normal conditions i.e. there is no connection to any part of a load in the device? Another way of asking is that there are no 120 volt loads in the device connected to that wire?

So to rewire this he would attach to red black and the long prong to green?

[dyount]

6/50 is 2 wire and green would of been "grounded" conductor .... which would of been the 3rd. With needing to switch to a 4 wire I'd switch to a locking 14-L50 myself. That way you've got no issue of getting the plug partially pulled out etc. It's a very typical connector for folks in the entertainment industry to wire dimmers etc.
As far as any arguments regarding the location of the round ground being up or down on 3 prong that will never end and is not in the NEC. Union guys typically wire with the 3rd in the up position and non union with it down.
My strength in "code speak" is not in NEC btw.... more of a fire/panic specialist with large occupancies/hi hazards

[cashflyer]

Originally Posted by GWN7

Buy a old style plug that fits your welder cord and replace the current up to code plug with the old style plug. The cost of this will be about the same as buying a adapter cord to fit. The down side to rewiring not to code is that if you have a problem with your house is your insurance company can refuse any and all claims you might make.

Wiring in the 3-wire receptacle will be the cheapest option.
If I had to buy one, they are $11 - but I still have the one left from pre-remodeling.
Not sure if the insurance company could deny a claim. It would still meet the code that was in effect when this building was constructed 30 years ago. Also, they would have to prove that the wiring discrepancy contributed to any loss. IE: If the garage burned down from a heater fire, they could not deny the claim over a wiring issue.

Originally Posted by dyount

The ground (bare or labeled green) is in this case an equipment grounding conductor. Step 1 check to see if somewhere in the connections of your welder pigtail you've got a spot to attach a ground to the metal parts of the welder? should be able to find. As well, with the age of your welder the cord is probably not in the best condition age wise at this point and can be replaced.
Step 2 if cord cannot be grounded to the welder I'd use a UL listed (non home made) transition cord if you have to.
History on this basic subject including dryers/ovens is that although a grounded conductor (the neutral) was present the frame of the appliance could become energized so a grounding conductor was added to the NEC.
In my opinion if the welder and it's current cord are in good condition I'd have no problem approving the newly installed receptacle with 4 and a transition to 3 if it's done with a listed transition plug.
Not an electrician but rather a International Code Council certified Master Code Professional

Welder is only a few years old and the cord is in excellent (like new) condition.
From what I have been reading on other websites, including some welding sites, the receptacle should be wired with the bare (green) wire to the ground pin of the receptacle. Hot legs to the hot pins, obviously. Cap and secure the white neutral wire since it is unused in this application

Correctamundo?

[dyount]

Switching to 4 wire is 2 hots 1 neutral 1 ground. Hots... are hot.... Neutral is grounded conductor going to panel .... "ground" being bare or green is equipment grounding of the case to the panel. Think of it as wiring a sub panel with 4 wires... 2 hot,1neutral,and ground with grounds separated from neutrals on the busbar with grounding bus isolated

[dyount]

Cash my best advice is to buy a transition plug and I'm willing to bet the plug splits the ground to both the neutral and ground of the 4 wire end. That way the neutral in the recp't can be wired into the female.
The white can't just be terminated in the box without attaching it to the screw provided.

Crap! one thing I didn't think of is.... did your sparky talk to your local fire marshal/elec inspector? He'd probably not care a bit with an existing piece of equipment that's already double insulated. We building "nazis" like problem solving before the problem rather than failure on a job site.

[rick-l]

Originally Posted by dyount

1neutral,and ground with grounds separated from neutrals on the busbar with grounding bus isolated

In my fuse box green, bare, white, the ground rod and the neutral from the split phase of the transformer on the pole all go to the same place.

The only difference is the green is not supposed to carry any current except under fault conditions.

If you tie green and white together green will be carrying some current.

[dyount]

To be somewhat clear have your sparky ask this. " I want to run 4 wire from the panel to the box, wire it to a 3 wire recp't with neutral wire added to ground ". That way if the current 3 wire welder is replaced someday the rec't can be changed to a 4 easily. If the answer is no use a transition plug.
Now someone ask me a fire/panic question so I can get my OCD out of the NEC

[dyount]

Rick 1 , your fuse box is a main and not a sub panel. In a main current comes in 3 with shared ground/neutral. Subs are wired 4 with neutral/ground separated.
Ground does carry only in a fault condition so it's the "grounding (in fault) conductor" with neutral being grounded conductor.

[carambola]

i'm seeing this another way,
does his welder have any circuit boards?
then we start to consider the cord feeders
when is the bonding?

[cashflyer]

I don't foresee this outlet ever being used for anything other than this welder (since it is at the welder station) however I may sell the place in 10 years..... So I guess I will buy a 4-wire receptacle and wire into the box. And buy a $50 transition. That way, all is legal and safe for the next owners.

But just you know this... you're to blame for my fun fund being down by $50 now!

Crap! one thing I didn't think of is.... did your sparky talk to your local fire marshal/elec inspector?

I know the county sent out an inspector to sign off the place after the remodel was done.

Now someone ask me a fire/panic question so I can get my OCD out of the NEC

Ok... so when I am welding and set the place on fire, is there a maximum number of doors that are allowed to be between the work area and escape? Is it acceptable to have to run through the offices?

[pete3799]

Only if you're screaming........and in your pajamas.

[dyount]

So if you're welding and set the place on fire.... ? "IF" you have an occ load of less than 50 it's one door side hinged that can swing into the shop... Or if greater than 50 figure .2" per occupant up to a number I can't remember and Section 1014 of the building code doesn't do exiting through intervening spaces in a house so it's all good........ ish
If the county sent someone already who's done and you can't see a reason to call them back just wire the 3 wire plug with the neutral and ground on the ground plug and call it done with the cord and save 50 bucks to spend on suspension bushings for the 911.
Problem solved........honestly that's what I'd do. Cause if the welder craps you can wire a 4 wire for the new one or if you sell the place and someone wants a different welder they can still safely wire a 4 with the wires you've already pulled.

[cashflyer]

Originally Posted by dyount

So if you're welding and set the place on fire.... ? "IF" you have an occ load of less than 50 it's one door side hinged that can swing into the shop... Or if greater than 50 figure .2" per occupant up to a number I can't remember and Section 1014 of the building code doesn't do exiting through intervening spaces in a house so it's all good........ ish

Feel better now?

Originally Posted by dyount

If the county sent someone already who's done and you can't see a reason to call them back just wire the 3 wire plug with the neutral and ground on the ground plug and call it done with the cord and save 50 bucks to spend on suspension bushings for the 911.
Problem solved........honestly that's what I'd do.

Put the white (neutral) and the green(eq ground) both into the ground lug? That's what I was originally thinking but wanted to be sure.


Oh... and my occupancy load is one. And my dog. So, two I guess.
Unless it's poker night, but we don't weld on poker night.

[billybek]

Is there a wiring diagram on the back of the welder?
If there are no 120vac loads I would imagine the ground is just a chassis ground for the welder.

I can't remember this exactly but I don't think you should be bonding a neutral to ground at a device/plug.