Dumb electrical question regarding wire colors

[Greg Funk]

I would like to convert a 240V - 20A circuit to 120V - 20A. The circuit is currently wired with 12AWG wire with black and red conductors.

Normally, black is hot and white is neutral. In this case the wire I have has black and red conductors. Is there a convention as to which one should be designated as hot?

thanks,

Greg

[Jim Becker]

I don't know about convention. But I'd use black as hot and mark the red line with WHITE tape to signify to you or someone in the future that it's being used as a neutral. Writing on said tape with a fine point sharpie isn't a horrible idea, either...

BTW, no electrical question is "dumb"...some of the answers supplied might be, but not the questions!

[Greg Funk]

I don't know about convention. But I'd use black as hot and mark the red line with WHITE tape to signify to you or someone in the future that it's being used as a neutral. Writing on said tape with a fine point sharpie isn't a horrible idea, either...

BTW, no electrical question is "dumb"...some of the answers supplied might be, but not the questions!

Thanks Jim,

That's what I did except the marking which is a good idea.

Greg

[Rick Gifford]

I would keep the black as the hot. Use the red as the "white".

Hopefully this thread doesn't turn into a major code discussion as most electrical questions seems to. Plus someone will be sure to tell you to hire a qualified electrician.

Might wanna mark them just so you will remember years later.

[Greg Funk]

Thanks Rick,

Sound like a consensus!

Greg

[John Hixon]

Absolutely, mark the red wire (neutral) with white tape. It's not just a good idea.

Wrap about three inches of the wire, close to the stripped end with white tape. An easy way to do this is to lay the tape along the length of the wire and then roll it around the wire to wrap it.

Make sure the power is off.

[David G Baker]

Greg,
Make sure you put white tape on both ends of the red wire. Another option that I use is to get white shrink tubing, slide it over each end of the wire and heat it up. One other thing you might have to verify is to make sure that there are no other boxes supplied by the existing wire/circuit.

[Greg Funk]

John, David:

Thanks, I'll find some white tape.

Does all 12-2 wire have red and black conductors? The cable has a red jacket.

Greg

[David G Baker]

John, David:

Thanks, I'll find some white tape.

Does all 12-2 wire have red and black conductors? The cable has a red jacket.

Greg

Greg,
I just thought of something when you mentioned 12/2 wire, does your wire have the third leg (the bare copper wire) used for ground?

[Greg Funk]

Greg,
I just thought of something when you mentioned 12/2 wire, does your wire have the third leg (the bare copper wire) used for ground?

Yes. Why do you ask?

Greg

[John Hixon]

12-2 should be black,white and bare copper. (Yellow on the new stuff and flat)
12-3 should be black, red, white and bare copper. (Yellow on the new stuff and kindof round)

Older wire doesn't necessarily match the colors of the new stuff.

14 ga is white
12 ga is yellow
10 ga is orange

And yes, I meant to indicate that both ends of the wire should be marked appropriately.

[Joe McCormick]

Just curious.
Is this wire a Romex type wire run thru the wall?
or
Is it individual wires run thru a metal or plastic conduit?

[David Duke]

Just curious.
Is this wire a Romex type wire run thru the wall?
or
Is it individual wires run thru a metal or plastic conduit?

My question exactly, I can think of no other reason for there not being a white conductor but then again when run in conduit I have never seen a bare ground run, normally it is run with green colored insulation.

[fred marcuson]

ok , another dumb electrical question ..
i was under the impression that 240 v has 2 hot leads , 1 black and 1 red + some sort of ground ??

[Greg Funk]

Just curious.
Is this wire a Romex type wire run thru the wall?
or
Is it individual wires run thru a metal or plastic conduit?

This was a partially through the wall and through a plastic conduit to a floor-mounted receptacle. I found a scrap of wire it is NMD90 XLPE 12/2 Red Red-Black Heatex cable. The colors make sense for a 240V circuit which is what this originally was.

Edit: I found the wire:
NMD90 (Red) HEATEX is a variant of NMD90 CANADEX, with NO WHITE WIRE in the 2 conductor cable. This cable is designed for use on 230-volt systems where there is no NEUTRAL, therefore the cable has a black and a red conductor in addition to the bare bonding wire. To make identification easier it is usually supplied with a RED overall jacket. It should NOT be used on 110-volt systems as there is no neutral, and it is dangerous to use either the red or the black as a neutral. Large sizes are available for use with electric furnaces.

Oh well. I wrapped lots of white tape on it. If I sell my house I'll put it back the way it was.

Greg