240v - mess with it? Part 2

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Old 03-17-13, 07:23 PM
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240v - mess with it? Part 2

Part 1 of this thread about rerouting the power to my A/C compressor was in 2009 and I'm finally getting around to the project. System won't let me reply to it.

I want to move the exterior (the small one, not the house box) pullout breaker box (60A 220V) for my A/C compressor so that the cable can exit the wall under an eave rather than under a gable end.

Looking back at the previous thread I still have a question. The problem is that I will need a quite a bit longer run of exterior conduit and if I understand right I can't make a splice inside the conduit. To have a continuous run of cable I would have to connect one end inside the A/C and it looks like I would have to dismantle it to do that.

The only alternative I can think of is to mount an exterior box to make the splice? Am I right? No splice allowed inside the conduit? Does making the connection at the compressor look worse than it is? It looks like the connection is directly to the compressor motor inside the fan housing.
 

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Old 03-17-13, 08:01 PM
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The only alternative I can think of is to mount an exterior box to make the splice? Am I right? No splice allowed inside the conduit?
Yes. In fact, splices can only be made inside boxes and other enclosures rated to enclose splices.

To have a continuous run of cable I would have to connect one end inside the A/C and it looks like I would have to dismantle it to do that.
Electrical cables are not installed in conduit. Individual conductors are used in conduit.

Am I assuming making the connection at the compressor will be more of a project than it is?
No way to determine that. What is the make and model of your condensing unit? Better yet, some pictures - of the nameplate, wiring diagram, wire terminations, etc. - would help us see what you're looking at.
 
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Old 03-17-13, 08:23 PM
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I'll post some photos. Maybe there's a connection panel on the exterior. Frankly I'm afraid of the thing, it was so expensive . . .

Electrical cables are not installed in conduit. Individual conductors are used in conduit.

Read more: http://www.doityourself.com/forum/el...#ixzz2NrGF8x6S
Oh yeah, forgot about that.
 
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Old 03-31-13, 12:24 PM
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Sorry for the delay. Mfr is Westinghouse.

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Old 03-31-13, 12:50 PM
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I've been unable to find wiring diagrams, only the owner's manual:

http://www.google.com/url?sa=t&rct=j...44442042,d.eWU
 
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Old 03-31-13, 01:28 PM
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Air conditioners are wired with 2 hots and a ground.
 
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Old 03-31-13, 01:47 PM
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There is a wiring access door on the compressor unit. With the unit powered down..... open the cover up and look inside. Usually the two hot wires go to a contactor and the ground goes to a ground lug. Should not be very hard to rewire.
 
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Old 03-31-13, 07:45 PM
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You should also find 2 smaller low voltage thermostat wires. No biggy.
 
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Old 04-01-13, 06:37 PM
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If there a thermostat wires, I will be extending those also - they should also run in the conduit along with the three AWG-10 conductor wires?

Also, I will have to extend the length of the cable inside the wall. This should be NM cable, with the extension spliced in a box, correct ? . . . then they to the 3 individual conductor wires in the pullout box and the wires run in conduit to the AC. Do I have this right?
 
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Old 04-01-13, 07:02 PM
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If there a thermostat wires, I will be extending those also - they should also run in the conduit along with the three AWG-10 conductor wires?
No.

Also, I will have to extend the length of the cable inside the wall. This should be NM cable, with the extension spliced in a box, correct ?
Yes, and the box must remain accessible.
 
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Old 04-02-13, 05:25 AM
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1. Not seeing thermostat wires running outside the existing conduit. There's a wire running along the copper plumbing tubes . . . buyt I thought it was a ground.

2. If the box for the splice has to be accessible it would have to be mounted on the exterior wall. That being the case I might as well forget about changing the location of the pullout breaker box and leave it where it is on the wall. The idea was to not have a box mounted on the walll under the gable end where the siding tends to rot. That makes life simpler altho I'll still be replacing the conduit and breaker box.
 
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Old 04-02-13, 05:42 AM
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1. Not seeing thermostat wires running outside the existing conduit. There's a wire running along the copper plumbing tubes . . . buyt I thought it was a ground.
Never heard of running a ground there but it is where they run the thermostat cable. If it is multi-conductor that is the hemostat cable.

You could run new cable long enough or put the splice inside in a flush box with a blank cover.
 
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Old 06-01-13, 06:17 AM
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So I've got siding off and all the wire/cable/conduit I need, plus a cute little torque wrench. A couple of final questions because there's no margin for error with a central A/C in Florida in June!! No downtime tolerable, say to run back to the store!

There was some concern in the previous (Part 1) thread about torque numbers for tightening connections to the screw contacts in the (exterior) pullout breaker box. I'll be
(a) splicing wires in an electrical box in the wall (to be accessible from house interior) to extend the NM cable along the wall,
(b) connecting wires from the NM cable and new wires to the conduit inside the exterior pullout box, and
(c) connecting the new wires coming thru the conduit to the A/C.

Should I be checking torque on all of these connections, or only in the pullout breaker box?

Any other precautions, like should I tape over splice caps or anything?
 
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Old 06-01-13, 12:18 PM
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Maybe I'm misunderstanding something here. Type NM cable is only rated to be run in protected spaces inside a structure. It is not rated for use in conduit, and it is not rated for use outdoors. Where are you using the cable and where are you using individual conductors in conduit? And where is the set of splices where one stops and the other starts?

So I've got siding off and all the wire/cable/conduit I need, plus a cute little torque wrench... Should I be checking torque on all of these connections, or only in the pullout breaker box?
Sure. You bought the cute toy, why not play with it
 
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Old 06-01-13, 05:03 PM
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Maybe you didn't read the original question?

I want to move the exterior (the small one, not the house box) pullout breaker box (60A 220V) for my A/C compressor so that the cable can exit the wall under an eave rather than under a gable end
Not getting your comment about the torque wrench. It's to torque the lugs in the pullout breaker box.
 
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Old 06-01-13, 06:27 PM
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Maybe you didn't read the original question?
I read it, six weeks ago. It wasn't your intent or goal I was seeking clarification on, it was your solution, so quoting that doesn't add clarity.

When you said
connecting wires from the NM cable and new wires to the conduit inside the exterior pullout box
today, I just wondered how the NM was getting to the exterior disconnect. Will it go straight through the wall and into the back of the box? Is the conduit you're speaking of just the liquidtight from the disconnect to the unit?

You can use your torque wrench to torque anything you like, I have three of them. I occasionally use one on panel, but they mostly come out just for the lugs in service gears.
 
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Old 06-02-13, 03:43 AM
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Will it go straight through the wall and into the back of the box? Is the conduit you're speaking of just the liquidtight from the disconnect to the unit?
Exactly.

BTW, I'm having a heck of a time with the (single slot) lug screws on the GE electrical disconnect. I've already destroyed the slots on two of them. Luckily the box only cost about $15. Problem seems to be not having a screwdriver bit that's thick enough, not finding anything thick enough for these slots. The screws are too small in diameter for a huge bit and the slots are too wide (sloppy fit) for any normal driver bit I can find. Trying to torque them to 32-35 in-lbs has been impossible so far. Is there a special tip size for these things? What's the trick I'm missing?

It sounds like you're saying you don't use torque wrench on most electrical connections? Only reason I'm obsessing about it is the recommendations I got to use one in responses to the previous post (Part 1). Has to do with resistance and overheating.
 

Last edited by suobs; 06-02-13 at 05:58 AM.
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Old 06-02-13, 05:50 PM
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Originally Posted by Nashkat1
Will it go straight through the wall and into the back of the box? Is the conduit you're speaking of just the liquidtight from the disconnect to the unit?
Exactly.
OK, I think I lost focus when you said something about mounting a J-box that's accessible from inside to make splices in. Reading back through, I think you were talking about a box where you could splice the existing Type NM to a new piece that will extend it to the new location for penetrating the wall.

I regret my confusion. Thank you for clarifying the design.

It sounds like you're saying you don't use torque wrench on most electrical connections?
That's right. One of the reasons is the difficulty you've been experiencing. One of the fittings I would never, ever, try to use a torque wrench on, BTW, is a straight slot. Those are too easy to mess up, even with a good hand-held screwdriver.

Two more points. One reason I don't often break mine out is that I've been doing this work, and working on engines, for a long time, and I can more-or-less feel when something is tight enough. And no, I can't teach that to you in words. It can only be learned by doing it.

One of the times my torque wrenches do come on the job, other than when we want to be careful with the connections inside a gear, is when we're helping one of our people upgrade his or her skills to include making up panels or gears.

The other point is that torque values are often specified so that the nut or lug bolt or whatever will be tightened enough but not over-tightened. This is almost always the reason they're specified for electrical connections. When you say
Only reason I'm obsessing about it is the recommendations I got to use one in responses to the previous post (Part 1). Has to do with resistance and overheating.
I'm all but certain that's the reason here. Distorting the conductor can and will lead to overheating in the lug. It is really, really easy to crank down hard enough on the bolt or screw in a lug to start to distort and flatten a solid conductor. A stranded conductor can be splayed to the point of being loose, or some of the strands can be broken. Either way, the whole point is to stop tightening the screw or bolt when the pressure on the conductor is likely to be optimum.

OK. Now, I'm curious about something you said:
Trying to torque them to 32-35 in-lbs has been...
The reason is that 32-35 in-lbs. is a very small amount of torque. It's equal to only 2.67 to 2.9 ft-lbs, or 37 to 40 kg-cms, roughly. Maybe the weight of a 12-pack hung on the end of a 12-inch rod. Can the wrench you bought be set to that small value? I think one of mine can but I would have to dig it out to be sure. That wrench is less than 8" long, has a 3/16" or 1/8" drive, and lives in a case, with its fittings, that can be carried in a hip pocket.

What's the trick I'm missing?
Tighten the lug screws to what feels like a reasonable tightness with a regular screwdriver. Then set your wrench and try to loosen the screw. If the screw loosens before the wrench pops, tighten it a bit more and try again. If it doesn't, you can loosen the screw by hand, strip a fresh end, and try again, tightening the screw less.

Or you can just call the torque good and move on.
 
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Old 06-09-13, 08:14 AM
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OK, got rained out last week. Latest question is: the box instructions and the labels on the terminals in the box say where the line and load wires go. But the existing box has them set up differently even though the terminals are labeled just the way they are in the new box. Should I do it the way the last guy did or follow the instructions?

The previous installer has both line wires on one side and both loads on the other side. The instructions and labels have both loads in the center terminals and both lines in the outer terminals.
 
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Old 06-09-13, 08:27 AM
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Can youexplain your last question so it can be answered with out reading the whole post and maybe add a couple of pictures to illustrate what you are talking about. Is it some kind of disconnect?
 
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Old 06-09-13, 09:42 AM
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Sorry, yes it's a 60A pullout nonfused disconnect. Also, I explained it wrong. He has the white load wire going to a center (load) terminal, and the black load going to an outer (line) terminal. He has the white line wire going to an outer (line) terminal, and the black line going to an inner (load) terminal.

Photo below - lower right hole is the conduit to the A/C, left is the cable from the house. The wire on the far right is actually the white wire from the NM cable. I'm not sure why it was taped.
 
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Old 06-09-13, 11:30 AM
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The two ungrounded conductors in the cable from the breaker box go to the line side.

Note: That white was supposed to have by code been remarked as an ungrounded conductor by putting black or red tape on it or recoloring it with felt tip marker or liquid insulation. Both whites should have been remarked. The position of the two ungrounded conductors in the cable on the line side is interchangeable. It doesn't matter what color line connects to what color load conductor because all are ungrounded conductors.
 
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Old 06-09-13, 11:36 AM
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If I understand right, you're saying to follow the instructions. Line (cable) wires to line (outer) terminals and load (conduit) wires to load (inner) terminals. Both grounds to the ground terminals. Right?
 
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Old 06-09-13, 01:07 PM
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Yes, that is correct, both line wires to the terminals marked LINE and both load wires to the terminals marked LOAD. All the wires should be some color other than white, grey or green.

Anticipating your next questions, the way it was wired was acceptable and the machine didn't know the difference, it was just a matter of the factory legends on the terminals. Same with the wire colors.
 
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Old 06-09-13, 01:31 PM
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The new wires are green, white and black in the conduit to match what was in there before. In the NM cable they are white black and bare. I left a third (red) wire in the cable unconnected. Are you saying to mark the white wires red with a marker or tape?
 
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Old 06-09-13, 01:46 PM
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I left a third (red) wire in the cable unconnected. Are you saying to mark the white wires red with a marker or tape?
Red would not be remarked because it is an ungrounded conductor color already. If you use a three conductor cable as you did you should use black and red and cap the white. You should only use white as an ungrounded conductor if there is only one ungrounded conductor (hot) available. You had red so you should have used red.

Any color but white, gray, or green may be used for the ungrounded conductors (hot). Any time a grounded conductor (neutral - white) is repurposed as an ungrounded conductor (hot) it must be remarked in some acceptable way an ungrounded conductor color.
 
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Old 06-09-13, 02:13 PM
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I can see that now but it's done, matching the previous wiring in the conduit and the existing cable so I could trace what I was doing. I'll recolor the white. It seems odd that the previous NM cable was 2-wire and was colored white, black, and bare. No red.
 
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Old 06-09-13, 02:22 PM
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No, that wasn't odd at all. The ONLY reason to use a three-conductor (insulated conductors, not including a bare equipment grounding conductor) cable is to have BOTH 240 volts AND 120 volts available. An air conditioning condensing unit is a 240 volt only piece of equipment. It does not require a neutral (white) conductor. The electrical codes recognize this and allow for the re-marking of a white wire to signify that it is NOT a standard 120 volt circuit.
 
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Old 06-09-13, 02:44 PM
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You really need to read a book such as Wiring Simplfied before you go further so you will understand what you are doing. Since you used 3-conductor cable you should correct your error not leave it to confuse the next person.
 

Last edited by ray2047; 06-09-13 at 05:28 PM.
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Old 06-09-13, 04:18 PM
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Done and whites marked red. The unused red is capped both ends.

Thanks for your help! I'll check out that book.
 
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Old 06-09-13, 07:54 PM
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Done and whites marked red. The unused red is capped both ends.
The NEC allows the white wire in a cable assembly to be redesignated and used as an ungrounded conductor if and only if there are only two insulated conductors in the cable.

You need to use the red wire and cap off the white.
 
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Old 06-09-13, 08:05 PM
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You need to use the red wire and cap off the white.
Echo Echo. I told him but he did anyway.
You should only use white as an ungrounded conductor if there is only one ungrounded conductor (hot) available. You had red so you should have used red.
 
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Old 06-09-13, 08:56 PM
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Echo Echo. I told him but he did anyway.
Yep. :NO NO NO:

Suobs, have you bought and read Wiring Simplified yet?
 
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Old 06-10-13, 07:04 AM
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Since the OP has conduit the correct colors should have been used. There should be no need to re-mark any conductor.
 
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Old 06-11-13, 06:36 PM
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OK, I didn't "did it anyway", it was already done that morning by the time you guys got back and brought these issues up.

I was following the original colors when I bought the wire and I had an extra 25' of cable . I was told in this thread there was nothing wrong with the way it was originally wired, it just hadn't been marked right at the ends. I was told to remark repurposed wires. In another thread ("NM cable 3-wire to 2-wire?") in this forum I was told that it was fine to leave an unused wire in 3-wire cable.

Nobody mentioned red vs. white; not that that is your fault - maybe I should have known that but:
  • The red in the cable is red at both ends and is capped at both ends (and the ends could be taped white). The whites in both the cable and conduit are remarked red. So it should be clear to anyone what is what. That's a lot of expensive 10-ga wire and cable to waste plus the time.
Frankly I am not seeing the problem, especially if I tape the red to white. But there are a lot of things about building codes that I don't get so I'll fix it. Thanks for getting back with these concerns!
 
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Old 06-11-13, 07:09 PM
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Re-identifying conductors in a cable is often acceptable under certain conditions. Re-identifying individual conductors in conduit that are smaller than number 4 is definitely contrary to the NEC but MAY be allowed by the LOCAL inspector under certain conditions. Re-identifying individual conductors in a short "equipment whip" such as between a local disconnect and an air conditioning condensing unit would NEVER be acceptable if the conductors were less than number 4.

Suobs, do you have a copy of Wiring Simplified? You should if you are going to be doing ANY electrical work.
 
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Old 06-11-13, 07:22 PM
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I do have a copy. No I haven't memorized it.

The conduit is a simple fix, just and replacing the white wire with red. The part about replacing the cable would be complicated, expensive, and very time-consuming, so if you are saying I can cover the red conductor in the cable with white tape and be done with that part I'd like to hear what the rules of engagement are.
 
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Old 06-11-13, 07:47 PM
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Disconnect the red-taped white wire from both ends. Remove the tape from the white wire on both ends. Install wire nuts on the white wire at both ends. Connect the red wire where you previously had the taped white wires.

You ONLY re-identify a white wire in a cable when there is no other wire to use. If you had had ONLY a white and a black then re-identifying the white to some other color (not green, or grey) would have been acceptable. It was the presence of the red wire in the same cable that made re-identifying the white incorrect.

Note, this is the general rule. Wiring of three-way switches will modify this rule.
 
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Old 06-11-13, 07:52 PM
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so if you are saying I can cover the red conductor in the cable with white tape and be done with that part
No you can not re-identify a red as a neutral if the wire is not #4 or larger. In any event this is 240 volt. A 240 volt circuit does not use a neutral so only the black and red should be used if this is a 3-conductor + ground cable. The white must be capped off. It is not used.

Back ground: A 120 volt circuit uses a grounded conductor (AKA Neutral) and an ungrounded conductor (AKA Hot). Only two colors may be used for the grounded conductor (Neutral) White and Gray. Except for green in a single phase circuit the ungrounded conductor (AKA Hot) may be any other color. Usually red or black but blue and yellow are common. There are very strict rules regarding when a white or gray wire #6 or smaller can remarked as an ungrounded conductor (Hot).

A 240 volt circuit use only ungrounded conductors(AKA Hot). If at all possible only colors not reserved for other purposes (gray, white, green) may be used. Since you only need two ungrounded conductors and a 3-conductor cable has those you must use the two that are intended for ungrounded conductors. That is the red and black.
 

Last edited by ray2047; 06-11-13 at 08:13 PM.
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Old 06-11-13, 08:03 PM
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So let me see if I have this right. Are you guys trying to tell me I can't re-identify a red as a white?

Just kidding!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
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