Just purchased 12-3 wire, but really don't need the red wire - OK to not use one of the wires?

Depends on where you are.

I am in Minnesota.

Also, i don't plan on ignoring ANY wire. I didn't mean to say I'd not use the red one. It's just that I don't know what to do with it.

I plan on meeting my inspector next month, and I am least 6 months away from starting. Eventually I will get the correct information through research.

It's just that, if I have to sell the 12-3, I'd like to do it ASAP.

Sure if the boxes are big enough for the extra conductor. Leave it 6" long, put a wirenut on it and coil it in the back of the box. You may end up using it some day.

A good practice IMHO, cant count the times I've needed an extra core for something.

| I am finishing my basement, and bought some 12-3 romex NMB for a | screaming deal. | | However, I don't need the extra red wire. Can I just leave it | unconnected when I wire up my outlets and lights? | | Or is 12-3 a really nifty upgrade and I just don't know it?

If you are not going to use the extra red wire, leave it there (at least as long as the others, or at least 6 inches) and cap it off on both ends.

You could use it in the following way to increase circuit capacity. But I do not recommend this unless each receptacle is direcly fed, instead of beind cascaded from one to the next. With the red wire connected to one pole (phase) and the black to the other, using a 2 pole breaker, you have a dual voltage 120/240 volt shared neutral circuit. On a receptacle there is a jumper fin between the upper and lower half on the hot side which you remove. Connect the red to one half and the black to the other half. Be sure the receptacle is a _single_ handle device. Now you can use 20 amps on the lower half _and_ another 20 amps on the upper half.

As an alternative, you could upgrade to a double size box and use 2 duplex receptacles with the red wire to one and the black wire to the other and the white wire shared between them.

I do not recommend than any amateur wire a shared neutral circuit unless it is _one_ circuit breaker to _one_ receptacle (which then must also have the slotting match the breaker capacity) or _one_ pair of receptacles in a single box. Since you don't know what the red wire could be used for, you do fall into the amateur category for this.