Has anyone on this forum ever installed or been asked to install the secondary conductors of a welder in conduit? What was your response?

Nope

My response would be along the lines of uses not permitted unless the leads said RHW or some other 310.13 insulation.

First off, No never been asked that.
But as a response,
First thought is...Why?. Kinda ruins the portability of the leads.
Then, what type of conduit are we talking about?
Then, If that is what you want...your the customer.
Conduit, Wire Size & Wire Type would all be factors to do the installation correctly.

Rob

When I was wearing the tools, I was asked to run the "hot" lead to several places in the building that was aboyt 20k square feet and then the welder was left in one spot (in the shop) and the person doing the welding only had about a 25' stinger lead that would be plugged in to various outlets via a cam lock type connector. The Ground was usually established via the piping or conveyers throughout the building.

The other installation where I was involved as the Inspector not an installer, had to do with a coupla sports events ( the US PGA Open and the Rider Cup) where the welder cable was used for feeders and branch circuits. This was however not in a raceway and this seems to be standard fare for this type of event. I'm not sure this is kosher but it sure worked well and was practical.

Any information on the use of welder cable for other than secondary conductors for a welder would be appreciated.

Bob,
As long as the welding cables are being used for welding, I see no reason why they can't be in conduit.
Don

Don how are you figuring that?

Welder output or not it is still a flexible cord.

George

I would not run one lead I would run both to the point of use.

George some welding cable carries the RHW insulation marking making it suitable for raceways.

I am not sure it is suitable for portable power cable unless marked as such.

All the temp generators we hook up we use what looks like welding cable but is labeled as portable power cable. The conductors must be run in close proximity to each other.

Bob- I wonder why you'd want to run both conductors to the point of use?

Edited for added thought- Does anyone have a source for information on the ampacity of welder cable? Nothing in the NEC to my knowledge.

[This message has been edited by George Little (edited 12-24-2005).]

Well doing it the way you described above seems like you could have a mighty hot conduit (assuming it is ferris) containing that one lead.

Bob,
Because Article 630 doesn't say I can't. Note, I am assuming that we are not talking about the power supply conductors to the welder, but the secondary conductors from the welding machine.
Don

Interesting point about the heating Bob. My 230a "buzz box" has the leads coming out separate bushings in a metal case I don't think there is a slot cut between them.

At our plant in some of the remote locations, are leads are ran together in conduit to a distribution box with two identified quick connects. That way they can hook up the welder at one end and hook their stinger and ground clamp at the other, one place in paticular nine stories up.

Tim

Bob,
Not if the output of the welder is DC.
Don

Bob,
For at least one manufacturer the only difference between their power and welding cable, aside from the listing and marking issues) is that the welding cable insulation that is 50% thicker than their listed power cable. Everything else is the same including the size, stranding, and type of material used for the insulation. We are actually prohibited, by the code rules, from using a superior product in this case.
Don

Cable marked "welding cable", and listed as such by UL, has been evaluated for use to as high as 100 volts- unless marked with a different (higher) voltage rating. I am not sure as to any sunlight or wet location ratings; it is safe to assume it is not evaluated for direct burial.

I would also assume that, following general trade practices, that you would need to run both cables in the same pipe- whether you had a DC welder, or not.

I do not see any code objections to running the wires in pipe. While they are certainly flexible, and certainly cords, welding cable is a specialty cable, and not a general use cord as are cords such as SO.

I will vote "no" on the sunlight protected issue. I used welding cable for the battery on my boat and the places where the sun hit it went bad.

John,
Why?
Don

Don I am not trying to give you a hard time but I don't understand your position.


Where is the permission to run the output in raceway or why do you feel 400.8 does not apply


Now you are just being argumentative.

For one I said could

It won't heat up if it DC, it won't heat up if the duty cycle is very low, it won't heat up if the welder is left off.

That aside IMO it would be a poor design choice, you will notice in my original post I did not say it was a code violation.

Gregg


Same with mine and any I can remember.

But manufactures do a lot of things we should not do in the field.

Why Even run Welding Cable in Conduit? Why not just Pull THHN? It Doesn't need to be flexible in the conduit?
I've done it before and I thought it was Overkill, Pulled like a Bear Too!

Bob,
I just don't see a real reason not to install the welding secondary cable in a raceway. After looking at the code sections again, I think that you are correct that it would be a violation. I am not ready to completely agree, as welding cable is not listed in 400.4 so I am not sure that Article 400 applies. I really want to delete the last 7 words in 610.15 and say that the code does not apply to the secondary conductors of the welding equipment, but that will have to wait a few years.
If you haven't noticed before, I like to be that way.
Don

[This message has been edited by resqcapt19 (edited 12-26-2005).]

Don, I did say "trade practices," as I realize that this issue is not one specifically covered in the code. Yet, where the code does discuss running couductors in pipe, it invariable says "all phase conductors will be in the same pipe (more or less)." The code does not distinguish between AC and DC on this issue, nor does it explain why the rule is present (we may deduce it is because of inductive heating issues- but our logic is separate from the code).

So, as a matter of practice, I would start from the position of running them together- and look for justification to do things different.

Considering the price of welding cable, my first impulse would be to run THHN in the pipe- and have some sort of "power point" to plug the cables into closer to the work. I am not there (at the jobsite), however, and I don't know the details- for all I know, running the wires separately, in pipe, over a distance makes a lot of sense.

I'd like to make a comparison, just for a moment, to something as simple as reading. Before we become authors or editors, we learn all sorts of things (i before e, etc). These form the foundation upon which we build- and our ability to communicate suffers when we deviate.
In electric work, the way it is supposed to happen is that first you learn how to do it, then you start learning the codebook. The NEC is pretty blunt about this, where it states plainly that it is neither a textbook nor a design manual. As with most good rules, it lays down general principles, rather than attempting to detail every possible variation. Without first understanding the foundation- the principles of the trade- your understanding of the code will suffer. This fear is probably at the root of my discomfort with "code seminar" inspectors (among others). But I wander....:-)

George,

I did this 25 years ago in a saw mill. It's been a long time but if I remember correctly we used 250 MCM type THHN copper conductor. We ran the hot lead only, the building steel was used for ground return to the welder. The hot conductors ran to several J-boxs around the mill where they were spliced to a short piece of welding cable with a female welding type connector on it. This short piece was attached to the box with a kellums type grip. The stinger could then be connected to any of these "hot boxes".
There were two or three welders installed this way. Each one served a different area of the buiding.
We also installed an illuminated push button at each "hot box" location. These push buttons were wired to a contactor that turned the welder itself on and off.
The state electrical inspector passed it and the system is still in use today.

[This message has been edited by Helectric (edited 12-27-2005).]

Thanks Helectric, that's my experience also. The system I installed was about 30 years ago and it's still in operation today. Works fine. We didn't get as fancy as you with a start contactor but we had the same type approach. The reason we did it was because we have several conveyers running in different direction and we couldn't get over the conveyers with the welder even tho it was on wheels. Our inspector didn't see a problem with it either.

???? Would the cable in metallic conduit have some current induced on it while used?


FYI I have been contimplating buying a welder... Everything one would not do with electricity normaly, just for fun....

Yup, getting the welders over and around equipment was the main reason for this system as well.
Since the illuminated start buttons are connected via a three wire control circuit all of them light up at the same time. This lets people know that a welder is in use so two people at different locations don't try and use the same welder at the same time.
The welder's heat setting is usually left at around 125 amps for 1/8" rod which is the size most commonly used there. Most of the time this eliminates the need to walk to the welder in order to adjust it.

[This message has been edited by Helectric (edited 12-27-2005).]

I am in a hurry now but I have to respond to this.


LMAO

Yeah I have noticed and have to admit I like to be that way to sometimes.

Have a great day, Bob