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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
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,Quote:
Originally Posted by Jim Becker
That's what I did except the marking which is a good idea.
Greg
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.
Thanks Rick,
Sound like a consensus!
Greg
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.
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.
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,Quote:
Originally Posted by Greg Funk
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?Quote:
Originally Posted by David G Baker
Greg
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.
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.Quote:
Originally Posted by Joe McCormick
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 ??
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.Quote:
Originally Posted by Joe McCormick
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
Greg,Quote:
Originally Posted by Greg Funk
Some 220 volt circuits do not need or use the third wire depending on the type of equipment that is being connected to it but it is best to have the third leg or ground wire for safety in a 120 volt circuit.
Rick,Quote:
Originally Posted by Rick Gifford
What's wrong with the "code discussions" that occur in these electrical thread?
Quote:
Originally Posted by Greg Funk
First, we need to remember that Greg lives in Canada, so the Canadian Electrical Code is the basis for their local code. I don't even know if the local municipalities have the ability to modify or decide what electrical code they want to use as is the case in the USA.
We know that there are circumstances when it's is permissible (even required) to reidentify conductors as being what we'd call hot. I was curious as to whether it's permissible to reidentify a conducter to be the grounded/neutral conductor, so I looked it up in the NEC.
The answer is No.
This is a section from the NEC, Article 200 - Use and Identification of Grounded Conductors.
200.6 Means of Identifying Grounded Conductors.
(A) Sizes 6 AWG or Smaller.An insulated grounded conductor of 6 AWG or smaller shall be identified by a continuous white or gray outer finish or by three continuous white stripes on other than green insulation along its entire length.
The key phrase is the last 4 words - "along its entire length." That means we can't reidentify a conductor to be the neutral.
Greg,
Electrically, what you're doing is not likely to give you any problems. I would, as you suggest, "put it back" when you sell the house.
Rob
Addy protocol: unlicensed, homeowner electrician
Sometimes nothing. Sometimes it gets argumentive. Sometimes folks are looking for a simple answer. In my area a homeowner can get by with doing it one way where if they hired a licensed electrician the electrician would be required to follow code. I can get by remarking the wire as a homeowner, but the electrician would have to pull new wire (just an example and not sure if this example is correct).Quote:
Originally Posted by Rob Russell
So many electrical questions end up pages long over code discussions when a person just asked if anyone had done it a certain way before.
So long answer short, we can make answers rather technical.
That is correct, there is , however, two ways to get 240, three wire and 4 wire. Appliances can have either.Quote:
Originally Posted by fred marcuson
Three wire, two hots, red and black, no neutral, and ground.
four wire, two hots, red and black, white neutral and ground.
the advantage of four wire, is a separate ground, that will create a safety ground on the chassis of the equipment, and should never carry current.
Both 3-wire and 4-wire circuits have an equipment ground wire. The advantage, for appliances, of the 4-wire circuit is that it is capable of providing both 120 and 240V whereas the 3-wire is for 240V only.Quote:
Originally Posted by John Hixon
Greg
there is no problem with identifying the red wire with white tape red jacket wiring is used for heating wiring also the wire you are identifying is not the ground wire but the neutral hope this helps