I'm going to use a 20' piece of 10-3 cord to feed both my welder and plasma mounted on the same cart. What is the best way to join the "extension" to the input wires? I was thinking cut both down to a short "pigtail", then twist, solder and wire nut; all within a small metal electrical box on the cart. Would this be OK? I was thinking ring terminals might not be as good as a direct connection.

The input wires are #12 each and the cord will be #10.

Why not use two outlets and the matching plugs on the machines? Keeps them portable without tieing them directly to the cart. You can also buy crimp lugs for wire that size. It would probably be a better choice than solder and wire nuts.

Later,
Jason

super permenant would be butt splide with solder and then shrunk tubed

No solder. Solder is for electronics, not electricity with the rare exceptions of specific connections.

I like the plug-and-receptacle opinion better, but if you insist on hard wiring: get a 4-square metal box and blank cover, (3) "Romex" 2-screw connectors (or "CGB's" ie strain relief connectors) that fit your cords, and simply use the proper sized wire nuts in the box. Make sure to ground the box as well. You could use a plastic box as well, you'll have to drill your own holes, by if you use the CGB's it would even be pretty weather/dust proof.


Leave the solder out if it.

why no solder?

lots of people sold their battery connections for winches and alts, they pull alot more amps than a welder.

Solder joints are not flexible and will break along with the copper wire that is soldered.
It has happened to me.

Sure people solder ring terminals on cable, and people sell the stuff to do it. I don't think a solder connection has any place in a cable that is going to see 3-400 amps going through it, like in a winch power cable. Solder has a much higher resistance than copper, a soldered connection that relies solely on the solder to connect the joint (like the solder slugs and ring terminals) will have a much higher resistance than a crimped or crimped and soldered connection. You should never rely on solder alone for a connection like that. Smaller gauge wires that can be joined via a strong mechanical connection, like twisting the strands back onto themselves and interlocking with the other wire, then soldered is okay, as there is a good copper to copper connection.

The higher the resistance of the connection, the hotter it will get during significant current draw, the hotter it gets, the higher the resistance gets, until it fails catastrophically. Age and oxidation make the connection less reliable.

I wouldn't say that solder has no place in wiring connections, although in this case, I would say, yeah, it has no place. It will be virtually impossible to get a good solder joint on this many wires of this gauge w/o resorting to a propane torch, once you take that road, you are going to f-ck up the insulation trying to get it done. There are better options, and actually a lot of them, even at your local home improvement store.

Later,
Jason

Whats the current rating on the machines? what size breaker is your #10 being tied into... more info before I could say if its a good idea or not.

solder is a no no in this case. Wire nuts, proper crimps or split nuts are pretty much the only choices to go with. Unless you want to get fancy and have a splitter box with lugs.

I'd recommend running the cords (with proper strain reliefs) into a 6x6 or 8x8 junction box with a set of terminal blocks and fuse blocks in it. Connect the hot #10's to a pair of terminals blocks, feed a set of fuse blocks for each load from those terminal blocks, and connect the #12 hots to the load side of the fuse blocks. If there's neutrals then jumper them on terminal blocks, ground the box and jump all the grounds together on terminal blocks or a ground bar.

I assume this is a pretty small welder or plasma cutter, because #10ga copper is only rated for 30amps and #10 Aluminum 25 amps.
A cable grip/stress relief would be nice but they are pricey. Last time I bought one they were $80 ea. For 110/240V no need for solder connections, ring terminals bolted to each other would not likely be to code. Just strip,twist, and use the proper sized wire nuts, and wrap with electrical tape so it pulls the nut tight. If you are worried about corrosion then use the wire nuts that are weather resistant, they have epoxy inside them.

I assume this is a pretty small welder or plasma cutter, because #10ga copper is only rated for 30amps and #10 Aluminum 25 amps.
A cable grip/stress relief would be nice but they are pricey. Last time I bought one they were $80 ea. For 110/140V no need for solder connections, ring terminals bolted to each other would not likely be to code. Just strip,twist, and use the proper sized wire nuts, and wrap with electrical tape so it pulls the nut tight. If you are worried about corrosion then use the wire nuts that are weather resistant, they have epoxy inside them.

You can get strain relief connectors for a lot less than $80. I am assuming your talking about the fancy ones with the wire mesh sleeve.

For a 4c 10g cabtire you should be able to get a decent connector for around $10.

Ring terminals can be used and bolted together (can be found in motor connections) and is up to code here as long as you use properly rated and approved ring terminals.

This is for a 40amp plasma cutter and 185 amp MIG welder. Both devices' max input is 25-28 amps. Thanks for the suggestions.

If you aren't crazy about the plug end ideas, What about using the old linemans splice? then shrink tube it, and mayge some friction tape for some of ease of mind. These splices are strong on a end to end pull

Why not use two outlets and the matching plugs on the machines? Keeps them portable without tieing them directly to the cart. You can also buy crimp lugs for wire that size. It would probably be a better choice than solder and wire nuts.

Later,
Jason

If I were to do it over I would do this, but run a 4 terminal plug and cord so I could have a couple 110 outlets on the welder cart.

I ran the 4-wire plug as suggested above. Used proper sized crimps throughout. Works great.

In my case, I made my "extension" cord out of 10-gauge 4-wire submersible pump cable. I joined 2 metal boxes (1 single, 1 double) with the appropriate fittings (all from Home Depot) and wired a duplex 110 and my welder plug.

All wires were connected with crimped #10 spade lugs, using "real" crimpers that I picked up a long time ago. These have replaceable dies and compound leverage, and do not damage the insulation.

Have not had a problem with this setup at all. Used a more basic setup for years with just my MM210. Recently added the 4-wire plug and 110's after reading a suggestion to do so here on Pirate when I set up my new shop and added my Plasma and Tig machines to the arsenal. All draw less than 30 amps, everything works great, and having less cords to tangle up/trip over/burn is a wonderful thing.

Since you only have #10/3c cord, a 120V outlet isn't on the menu.

Use a 4x4 deep or 6x6x4 box. Make good twisted-up pigtails and use an appropriate sized marrette. Put some dielectric grease in there if you have fear of corrosion.

Code (CEC anyways) allows only silver solder for connections. I haven't had a job yet where I felt the need to make that kind of splice.

This is the style of connector I like for cords. Iberville (T&B) makes one too.
http://www.lappusa.com/11012description.htm

this thread taught me two good canadian words

cabtire: SO cord
marette: wire nuts