How to connect #12 stranded to #10 solid

The only stranded - solid connection that I trust is solder. You'll likely get about 37 other different opinions...

You can 't> I have to make some connections inside an electrical box between #10 solid

Use pliers to twist and tighten the stranded wire onto the solid and then twist your wire connectors onto the splice.

why are are we connecting #10 & #12 conductors?

which wire is upstream? & what is capacity of the circuit breaker?

cheers Bob

I am hardwiring a transfer switch. The cable from the generator is solid

These will clamp those wires together tighter than a bull's backside in fly season:

Jeff

I thought a connection that relied on solder was a code violation?

Tin it with solder? Will it hold together when I twist it?

i agree. it may be overkill, but its cheap, easy, and works every time.

randy

Maybe you are using the wrong size of wire nut.

yup. if you tin it, not encase it....

randy

regular old red scotchlock/ideal wirenut/wingnut twist the stranded line it up with the solid, clip the ends off evenly, then poke em into and then twist the wirenut.

I would use wire nuts that have a brass insert with a set screw that you tighten onto the wires, after trimming the excess hanging out the insert you screw on a plastic cap. When finished it looks just like a twist-on wire nut. A "Marr #2 insulated wire connector" is listed as good for two solid or stranded #10 wires down to five #14s.

I was all set to sold the wires, but these look like they ought to be plenty secure; if anyone locally has them. Thanks

Yes, it is -- but if fastened with a wire nut, the connection relies on the nut, not the solder.

Sure will. Try it and see.

I think somepeople's option against this is, if you get a short, or a groundfault, the solder could melt and break the circuit. I think people want faults handled by protective equipment, not the wire itself. Imagine you overload the circuit and your connections come undone. :(

later,

tom @

Yeah. I think it's in the wiring methods article. Don't remember the exact section off the top of my head.

later,

tom @

This would concern me, maybe I have the wrong sized switch.

Might want to do further research into the setup.

later,

tom @

The switch is rated to 21a (240v), so #12 internal is fine, but the line going to it (about 80') had to be #10/3.

Actually I only plan on using it for 14a (120v) so #12, or even #14, would have been fine; but it seemed prudent to set it up for a larger generator since the work is about the same.

i dont believe tinning a wire before nutting it is 'relying on solder', but i could be wrong..

randy

Ditto this, I have used these for decades. Best thing for stranded, or mismatched sizes, or large bunches. Ideal brand used to make them.