Community Forums

Ramblin · 08-03-2013, 04:08 PM

I'm about to convert the welder outlet in my shop to a 4 wire RV outlet so I can plug in my coach. Afterwards, I will need to build a dogbone to go back to the welder outlet from the 4 wire RV outlet so that I can plug in my welder when necessary.

The welder outlet is 2 hots and a ground, all #6. There is a bare wire ground conductor in the outlet box that is unused, but connected to the ground bar in the panel along with the white (with green tape marking).

I intend to move the white to the neutral bus in the panel, and hook up the 4 wire outlet in the box, using the previously unused bare ground. I will remove the green tape markings at that time.

I have a 5' length of 6-3 that has a rubber jacket, and three #6 conductors; red black and green. My concern is, the bare wire ground in the outlet box is smaller than #6 gauge. Might be #8 or even #10. I suspect I may overload this conductor if I connect the welder's ground to it.

So, my question is, does the ground conductor for a welder outlet need to be sized to carry 50A? Secondarily, can I wire the welder's ground to the neutral of the RV socket (essentially using it as a ground) since the ground and neutral are bonded in the panel box?

Rich and Cork · 08-03-2013, 04:53 PM

This should help you out:

The 50-amp 120/240-volt 3 pole 4

FlyingDiver · 08-03-2013, 04:58 PM

Quote:

Originally Posted by Ramblin

So, my question is, does the ground conductor for a welder outlet need to be sized to carry 50A? Secondarily, can I wire the welder's ground to the neutral of the RV socket (essentially using it as a ground) since the ground and neutral are bonded in the panel box?

Q1 - No, because the welder is a pure 240V load, so it doesn't need a neutral. And the ground does not have to be sized for the full load because it's only a safety for stray voltage. Your welder should cut off before it gets to a full load.

Q2 - you're not supposed to do that, as far as I know. Just connect it to the ground line.

Ramblin · 08-03-2013, 04:59 PM

Quote:

Originally Posted by Rich and Cork

This should help you out:

The 50-amp 120/240-volt 3 pole 4

That doesn't really answer my questions, but it did tell me that #8 is OK for 50A runs less than 25 ft. Useful information, and a great addition to my bookmark collection. Thanks!

Ramblin · 08-03-2013, 05:04 PM

Quote:

Originally Posted by FlyingDiver

Q1 - No, because the welder is a pure 240V load, so it doesn't need a neutral. And the ground does not have to be sized for the full load because it's only a safety for stray voltage. Your welder should cut off before it gets to a full load.

Q2 - you're not supposed to do that, as far as I know. Just connect it to the ground line.

Excellent, thanks for the info.

Tony Lee · 08-04-2013, 05:44 AM

Sounds like the next post might be along the lines of "Help!!!! I just plugged my new motorhome into my new DIY 50 amp outlet and all the smoke escaped from the converter, TV, sound system, and fridge. Sob!!!!!"

Ramblin · 08-04-2013, 05:45 AM

Quote:

Originally Posted by Tony Lee

Sounds like the next post might be along the lines of "Help!!!! I just plugged my new motorhome into my new DIY 50 amp outlet and all the smoke escaped from the converter, TV, sound system, and fridge. Sob!!!!!"

I think not.

wa8yxm · 08-04-2013, 05:59 AM

It is standard for the bare wire ground to be smaller on large current (50 amp) circuits. I like your plan.

On the adapter to the welder.. (Why not just replace the plug on the welder) you need to know if the welder uses 120 volt or not (I assume not) but some 120 devices use 120 volt fans or such) if it does, Hook up hot-hot-neutral, if not hot-hot-ground.

Ramblin · 08-04-2013, 06:02 AM

Quote:

Originally Posted by wa8yxm

It is standard for the bare wire ground to be smaller on large current (50 amp) circuits. I like your plan.

On the adapter to the welder.. (Why not just replace the plug on the welder) you need to know if the welder uses 120 volt or not (I assume not) but some 120 devices use 120 volt fans or such) if it does, Hook up hot-hot-neutral, if not hot-hot-ground.

I could do that, but I need to be able to take my welder to other locations that have a standard receptacle.

Gary RVRoamer · 08-04-2013, 08:15 AM

You need to run a neutral to that outlet to get the required 120v for your RV 50A connection. The neutral is a current carrying wire, so must have insulation - you cannot use the existing bare ground as a neutral. Besides, you still need a ground wire in that circuit as well.

Change the outlet to a standard RV 50A model - a NEMA 14/50R. Then make a dogbone to plug the welder into it, using the two 50A hot wires and ground only - nothing to the neutral (which the welder does not use). The dogbone is basically the old 50A welder outlet wired to a NEMA 14/50P plug. Alternatively, just hardwire the old welder outlet to the new outlet, using a separate wall-mounted outlet box. It's probably a code violation to share that circuit way, though, unless you put a transfer switch on it so that only one of the two outlets can receive power at any one time.

Ramblin · 08-04-2013, 08:23 AM

Quote:

Originally Posted by Gary RVRoamer

You need to run a neutral to that outlet to get the required 120v for your RV 50A connection. The neutral is a current carrying wire, so must have insulation - you cannot use the existing bare ground as a neutral. Besides, you still need a ground wire in that circuit as well.

Change the outlet to a standard RV 50A model - a NEMA 14/50R. Then make a dogbone to plug the welder into it, using the two 50A hot wires and ground only - nothing to the neutral (which the welder does not use). The dogbone is basically the old 50A welder outlet wired to a NEMA 14/50P plug. Alternatively, just hardwire the old welder outlet to the new outlet, using a separate wall-mounted outlet box. It's probably a code violation to share that circuit way, though, unless you put a transfer switch on it so that only one of the two outlets can receive power at any one time.

The neutral is there already (being used as a ground, I mentioned it has a green tape marking in it). That will be the neutral for the RV outlet. There is a bare copper ground that is currently unused that will become the ground.

Tony Lee · 08-04-2013, 08:46 AM

Quote:

Originally Posted by Ramblin

I think not.

Perhaps, but in matters electrical, I'm a firm believer that if you have to rely on unverified advice on a public forum, it might be safer for you and the general public and any proper electricians who might come after you, if you left it to licensed experts.

Ramblin · 08-04-2013, 09:17 AM

Quote:

Originally Posted by Tony Lee

Perhaps, but in matters electrical, I'm a firm believer that if you have to rely on unverified advice on a public forum, it might be safer for you and the general public and any proper electricians who might come after you, if you left it to licensed experts.

I am not a 'proper licensed expert electrician', but I am certified by my state and county to perform electrical installations and modifications on my property. I took (and aced) the required tests to gain that certification prior to wiring the house I live in, and all of the outbuildings on my farm. Any new installations I do must adhere to code, and be inspected by the county prior to being energized, just like any 'proper, licensed, expert' electrician. I have a pretty good idea how to properly wire an RV outlet.

My question was very specific, and had absolutely nothing to do with the premise (permanent) wiring. It was: 'Does the ground conductor in a welder circuit need to be sized to carry 50A'. I included the information about the welder to RV outlet conversion to spare the respondents from needing to comment on that part, because I already have that covered.

One person (you) felt the need to respond anyway with snarky remarks unhelpful to the OP (me) and generally wasteful to the community (everyone who had to read it).

I would respectfully request that in the future, you confine your contributions to my threads to relevant information. Your uneducated opinion of my abilities, and your opinion of the validity of advice offered by forum members here do not fall into that category.

Tony Lee · 08-04-2013, 10:11 AM

The code will have tables showing the size of ground wires relative to either the size/rating of the active conductors or perhaps in some special cases, the rating of the circuit breaker protecting the circuit.

I say again, if you have to ask, then get advice or assistance from a licensed tradesman instead of from a public forum where there is no way to verify the contributors' credentials.. Or since you are fully qualified and accredited, read and understand the relevant sections of the code.