Powered welding cart

[Debriefer]

I got to thinking the other day that I'd like to have multiple angle grinders on my welding cart, so I don't need to change the discs so often, but then I realized I'd have to have a second extension cord (along with the one for the welder itself that I drag along already).

Is it really such a stupid idea to have a welding cart that has a receptacle bolted to it which grinders plug into? This is under the assumption that it's possible to safely get 120v from the 240v line for the welder. I of course would not be using more than one of the grinders nor the welder at the same time.

Wall-----extension_cord----cart----welder+grinders

This is probably not "worth it" but I am curious anyways.

 

[Duker]

I added power to my welding table and it has been great having multiple tools plugged in and ready to go. If safely done i.e. grounded properly etc. can't see why you shouldn't explore it further.

 

[Norcal]

Cannot tap a 15 ampere receptacle off a 30/40/50 ampere line. A small loadcenter & a 4-wire cord may work.

 

[Duker]

Cannot tap a 15 ampere receptacle off a 30/40/50 ampere line.

Nice catch by Norcal. He is right. I totally missed that in my thought process as I was focusing on the functionality.

 

[C96]

[/QUOTE]

That setup is sweet!

 

[iagsxr]

Cannot tap a 15 ampere receptacle off a 30/40/50 ampere line. A small loadcenter & a 4-wire cord may work.

It'll just have to have it's own breaker mounted on the welder.

When I got my first little wire welder a hundred years ago that's what we did so it was protected plugging into a standard welder outlet.

 

[sberry]

You would need a 4 wire cord and additional breaker protection. Generally this is not a great idea, run a light cord to your work area and be done with it.

When I got my first little wire welder a hundred years ago that's what we did so it was protected plugging into a standard welder outlet.

Not right either. This is one of those things at first glance may seem great but has so many code problems and hidden subtle problems its not worth it. If it was the welder mfg would all be racing to add it as some wonder feature.

 

[iagsxr]

I'd like you to explain the subtle problems.

Growing up we used to have big events at our house. My old man made a 100' drop cord to run out in the yard that he plugged into the welder outlet in the garage with 110 outlets on the end of it.

Coffee pots, lights, all manner of things were plugged into that over the years with no issues.

The only thing I will say is that the old garage had a fuse box so one leg of the welder outlet would have been on a 25-30a fuse rather than a breaker.

 

[sberry]

It can work and be unsafe. Now coming from 4 wire fed panels adds another layer to the problem.

 

[iagsxr]

K, I don't understand.

FWIW at our old shop I was going to make an "All-Terrain" cart for my MIG so I could more easily take it out in the gravel driveway and work. Was going to use my 3-wire 50' drop cord. Hardwire the cord to the welder, then pull off one leg for 110 outlets on their own breaker mounted to the cart.

Never built the cart before we closed shop, but my electrician was on board with the idea.

I'd really like to understand why this is a bad idea.

 

[sberry]

I was going to ask you,,,, if your electrician thought this was a good idea?

 

[Bjm364]

You could use a P&S L5130 plug and receptacle with a piece of 10/5 sjo hard wired to a jbox on your welding cart with your welder receptacle in a garvin cover. Put a short pipe ****** with another jbox with a double duplex garvin cover with receptacles for the grinders. Wire it so you have the red and blue in the cable wired to the 240 for the welder, and the black and white to the grinder receptacles. I would pipe the receptacle on the wall straight to the panel, so you could pull the appropriate conductors. That would give you large enough wire to safely run 30A to the welder, and you could put the 120V on a separate 20A breaker. That's how I would do it in my garage, but do whatever you think is safe.

 

[sberry]

I done this every way they invented. There is no better way than to make the place as friendly as it can be for a drop cord for tools to where you are working. (I used 14 wire on a couple benches I built with multi recepts and it should be 12) but a recept under a bench near a vise for a drill and grinder and one on each side of a bench where walked around, near the corner best I can. My benches are an island and have a pipe sub floor,, coming from overhead got in the way.

 

[sberry]

Hang a cord in the corner to reach out the door, use if for other chores besides welding.

 

[iagsxr]

I was going to ask you,,,, if your electrician thought this was a good idea?

He didn't see a problem.

Do you care to explain it?

 

[RickP]

He didn't see a problem.

Do you care to explain it?

I think it's because 15a and 20a outlets are prohibited on a 30a (or higher) circuit. I'm not a code guy, but another member might be able to give you the NEC reference. Sure, you can wire it up so it works (and I have friends who've done it) but when the smoke leaves the outlet, it's hard to get it back in.

 

[Zeke]

Even I can explain it. Whether the OP's welding extension cord is a 3-wire (mine is) or a 4-wire, there are 1 and possibly 2 problems:
Both the other hots are protected by a 30 A or bigger breaker. The grinders likely have 16 ga. cords. So using one side is not protected properly and certainly will not be a GFCI as required.

If a 3-wire there is no equipment ground to install a GFCI on the cart. Sure, they work with just a hot and a neutral, but that's not the code.

I think you can see why you don't plug a grinder into one side of a 30 or bigger circuit.

If the OP has the proper 4-wire 240v cord, he could possibly hardwire a multi receptacle extension with a built in GFCI and breaker. However, even then the cord itself would be overprotected. So that's not the best idea either.

The answer lies above in powering a small breaker box and plugging the welder and tools into properly protected plugs.

Now I have to laugh a bit. Since the cart outside is a detached structure, does it need a ground rod? lol

I think it's because 15a and 20a outlets are prohibited on a 30a (or higher) circuit. I'm not a code guy, but another member might be able to give you the NEC reference. Sure, you can wire it up so it works (and I have friends who've done it) but when the smoke leaves the tool, it's hard to get it back in.

fify

 

[RickP]

Now I have to laugh a bit. Since the cart outside is a detached structure, does it need a ground rod? lol

fify

Thanks Zeke.
You're right about the tool in the OP's question.
I was thinking about my friend who plugged lights into a cobbled up 240v cord.

 

[alwaysFlOoReD]

I have a bunch of $20.00 grinders so I don't have to swap out discs.... yes, I'm lazy! But they were all over the place and if in one place the cords would tangle. So I made a grinder tree;







I shortened all the cords but that didn't work too well as they would pull apart too easily. One of the things I plan on doing is replacing all the cords with better, more flexible, -40c capable 15'-20' long cords.....unheated shop. I will attach electrical outlet boxes to the base to save time plugging and unplugging cords. Told you, I'm lazy! A 5 gallon pail will control unused cords. Some muffler tube welded to the mast will hold my two drills.



Richard

 

[Norcal]

K, I don't understand.

FWIW at our old shop I was going to make an "All-Terrain" cart for my MIG so I could more easily take it out in the gravel driveway and work. Was going to use my 3-wire 50' drop cord. Hardwire the cord to the welder, then pull off one leg for 110 outlets on their own breaker mounted to the cart.

Never built the cart before we closed shop, but my electrician s on board with the idea.

I'd really like to understand why this is a bad idea.

Because it's a bad idea all around, first your tapping a 15 ampere 120 volt receptacle off a 30/40/50 ampere supply (you did not say what it was) but is not allowed by code, second using the grounding conductor as a bootleg neutral, this is aways a bad idea, under the wrong circumstances you risk electric shock.

 

[Norcal]

You could use a P&S L5130 plug and receptacle with a piece of 10/5 sjo hard wired to a jbox on your welding cart with your welder receptacle in a garvin cover. Put a short pipe ****** with another jbox with a double duplex garvin cover with receptacles for the grinders. Wire it so you have the red and blue in the cable wired to the 240 for the welder, and the black and white to the grinder receptacles. I would pipe the receptacle on the wall straight to the panel, so you could pull the appropriate conductors. That would give you large enough wire to safely run 30A to the welder, and you could put the 120V on a separate 20A breaker. That's how I would do it in my garage, but do whatever you think is safe.

5-wire devices are made for 120/208 volts* 3 phase wye systems
, NEMA came up with all different configurations for different voltages/amperages/phases to prevent connecting to the wrong ones & then there are people trying to foul it up.

*There are 480/277V & 600/347V models but it still applies...

 

[Cb-man]

Not to hi jack the thread but just had a quick question as I thought about doing this as well.

But I only have a 120V mig welders.

I was going to buy a 50ft heavy gauge extension cord cut the end off and wire it into an outlet on my welding cart. that way I have a place to plug in the grinder.

It will be handy but I use air tools for the most part anyway. Die grinders

 

[brewchief]

I have always planned on building a welding cart that can handle a couple welders or a welder and plasma cutter. I planned on using a 4 wire cord powering a 6 or 8 circuit load center(probably outdoor style as I think the cover would keep out grinding dust better).
I figured wiring two plugs for the welders and then a 120v 20 amp gfci circuit for grinders, chop saw etc.

Would doing it this way be safe and code legal or am I overlooking something?

 

[ishiboo]

You can definitely do it and do it safely if you use a 4-wire cord on the cart and outlet on the home, and have a 15A or 20A breaker on the cart when you split off the receptacle. But once you do all this, it'd be simpler to just have a second plug on the cart for that service.

If it bugs you having two cords, get a Marinco cord wrap which is designed for a 30A shore power cord (thick) and smaller items as well.

 

[ishiboo]

I have always planned on building a welding cart that can handle a couple welders or a welder and plasma cutter. I planned on using a 4 wire cord powering a 6 or 8 circuit load center(probably outdoor style as I think the cover would keep out grinding dust better).
I figured wiring two plugs for the welders and then a 120v 20 amp gfci circuit for grinders, chop saw etc.

Would doing it this way be safe and code legal or am I overlooking something?

A plug-in device like a welding cart would be UL-listed for safety. You won't be having it certified, so doing it safely is sufficient.

A 4-wire cord with load center would be fine safety-wise. Do consider how welding circuits are sized and how it will affect you now that you have outlet(s) on it doing other things which may be constant, if you are welding at the same time or have more than one large receptacle circuit.

Consider that when you mount load centers, electrical outlets, etc. to a metal cart, you typically do so with a metal load center, metal conduit, metal boxes, etc. These should be isolated from the welding table surface (and thus the metal cart if it's welded/bolted/etc. together where the two are connected electrically) so that it is not connected to the EGC, but only through the welding machine's work clamp. This is different than any other metal "appliance" where the metal case/etc. is bonded to the EGC. It's also a safety hazard if the cart becomes energized due to short/etc., I would DEFINITELY have GFCIs and even perhaps try a GFCI spa breaker on the garage's receptacle side. Easiest way to do this is with PVC boxes and a piece of wood or plastic to hold the load center box. Like any sub panel you'll need a separate ground bus not connected to neutral in the carts load center.

 

[sberry]

Norcal hit the bootleg neutral. In the old days the line that the op was talking about where dad made a cord to power the parties came from a fuse panel likely,,, one designed as service equipment with a bonded N, it didn't have a ground when it was done this way.

Yes, it can be done and when I started my wiring career and needed to add every scheme I could dream it might have been something I would have done. Today simply wouldn't bother. Got a small cord reel to serve that area.

 

[sberry]

If I read ish right he is worried about grounded tools on the table and the egc carrying welding current. I would have to think this thru but with a but with a table not bonded to the electric via some other source such as community welding grounds probably not an issue. If you have 2 grounded benches and forget to move a welding ground could use the egc as a pathway.

I have steel building, bench grounded to it and the electric with steel, no egc and fed 2 wire gfci. Multiple benches bonded with steel (are grounded for fault just not from the 120 circuit)

 

[cnc-me]

Just mount a cord reel to your cart. Cut off the female outlet and put on a plug.
Wire what used to be the feed end, to an outlet and you are set, no screwing around winding up cords ect.

 

[ishiboo]

If I read ish right he is worried about grounded tools on the table and the egc carrying welding current. I would have to think this thru but with a but with a table not bonded to the electric via some other source such as community welding grounds probably not an issue. If you have 2 grounded benches and forget to move a welding ground could use the egc as a pathway.

I have steel building, bench grounded to it and the electric with steel, no egc and fed 2 wire gfci. Multiple benches bonded with steel (are grounded for fault just not from the 120 circuit)

I'm not worried about welding current at all, the big safey hazard is if something goes wrong and the table is electrified via other means.

A steel welding bench should NOT be grounded to your building/EGC/etc.

 

[iagsxr]

Norcal hit the bootleg neutral. In the old days the line that the op was talking about where dad made a cord to power the parties came from a fuse panel likely,,, one designed as service equipment with a bonded N, it didn't have a ground when it was done this way.

If I understand correctly we're still bonded neutral where I live.

 

[sberry]

You are at the service main.

 

[sberry]

A steel welding bench should NOT be grounded to your building/EGC/etc.

Yes it should be, all metal with potential to become energized should be grounded.

I'm not worried about welding current at all, the big safey hazard is if something goes wrong and the table is electrified via other means.

Again, no ground no fault return,,, it should be grounded.


The reason to worry about the welding current is that we don't want it to take a pathway over or thru a ground wire in the electric system, a cord from a tool laying on the bench could carry welding current etc.

An example,,, 2 separate benches with circuits attached. Weld on one, all is fine, forget to move the welding ground to the other and an arc would be carried via the ground wire in the electric, the solution here is to put a heavy bond between tables to carry welding current.

 

[ishiboo]

Yes it should be, all metal with potential to become energized should be grounded. Again, no ground no fault return,,, it should be grounded.


The reason to worry about the welding current is that we don't want it to take a pathway over or thru a ground wire in the electric system, a cord from a tool laying on the bench could carry welding current etc.

An example,,, 2 separate benches with circuits attached. Weld on one, all is fine, forget to move the welding ground to the other and an arc would be carried via the ground wire in the electric, the solution here is to put a heavy bond between tables to carry welding current.

Exactly wrong. As I said it's different than most "metal things" where that is very true. As I said before, it is a risk if there was a short as it wouldn't create a fault to the EGC which would (hopefully) clear the breaker, so having a GFCI would definitely help.

NEC/commentary:

630.15 Grounding of Welder Secondary Circuit.
The secondary circuit conductors of an arc welder, consisting of the electrode conductor and the work conductor, shall not be considered as premises wiring for the purpose of applying Article 250.

Connecting welder secondary circuits to grounded objects can create parallel paths and can cause objectionable current over equipment grounding conductors.

Also, remember the welder does not have a ground or negative lead, it has work leads. The "ground clamp" may be positive, such as FCAW welding.

 

[sberry]

630.15 Grounding of Welder Secondary Circuit.
The secondary circuit conductors of an arc welder, consisting of the electrode conductor and the work conductor, shall not be considered as premises wiring for the purpose of applying Article 250.

Get no argument there. Does not say bench should not be grounded.

Connecting welder secondary circuits to grounded objects can create parallel paths and can cause objectionable current over equipment grounding conductors.

This is true, it is a situation but not an allowance to violate a code. Means the installer should consider this.

The "ground clamp" may be positive, such as FCAW welding.

Sure but the current wouldn't care..

Should be grounded,, could become energized from another circuit not only from the one supplying power to it. This metal isn't different than "other metal",, its metal that personnel can come in contact with and some step potential differences between it and the ground you are standing on.,,, most of this is way over my pay grade but welding on a metal building,, its all connected together, you weld on electrically connected equipment all the time. Just important to be sure you are not overheating a small wire between items with large welding current.

 

[ishiboo]

Get no argument there. Does not say bench should not be grounded.

It says that it's not included in the grounding requirements.

Do you connect a EGC to a tractor, skid loader or trailer when you weld on it? What about a standalone steel piece?

This is true, it is a situation but not an allowance to violate a code. Means the installer should consider this.

No code requires it to be grounded. And the suggestion is that it NOT be. This is an area for discussion as there is no "right" or "wrong" and different vendors have different suggestions.

 

[sberry]

We really need to draw some pictures here for the variables. As I said, I have a common point of ground for welders that go to the bench and no wire , use a 2 wire gfci but at the point the welders are connected there is a wire from the electric to that. A fault from any source would be returned to the panel, a pinched ungrounded conductor from another circuit from a cord etc.


BTW, some of my shabby explanations do not help.

 

[ishiboo]

We really need to draw some pictures here for the variables. As I said, I have a common point of ground for welders that go to the bench and no wire , use a 2 wire gfci but at the point the welders are connected there is a wire from the electric to that. A fault from any source would be returned to the panel, a pinched ungrounded conductor from another circuit from a cord etc.


BTW, some of my shabby explanations do not help.

Your explanations are good, it's just an area open for debate There is no right or wrong answer here just our opinions

 

[sberry]

We got some minds greater than mine on here but I don't know of an exception other than the wording in the code that says,,, metal likely to be energized,,, I would think a steel workbench would fall well under that. Mine is grounded,,, not with the supply conductors though,,, but,,,, they are gfci.