220 v receptacle, electric range

I suggest you hire someone who knows how to tell the difference.

having said that, older ranges often used the ground wire as neutral, something that is no longer allowed.

likely, 2 of the wires are hots, and the third is ground.

First off, it sounds like you're not that familiar with this sort of stuff so I STRONGLY recommend you hire a professional to do this.

That said, where are you located? If you're in NA then chances are BOTH black wires are hot. The red may be ground, I don't know for certain. Again, hire a professional, it's the only safe route in this case. TTYL

Your points are well taken. I am not against hiring an electrician and will do so, but in the meantime I still have some curiosity as to how things work. I was just wondering, assuming the red wire is hot, is there any way to tell other than trial and error, which of the two black wires is neutral or ground. I haven't been able to find this wiring arrangement in anything I've read so far. kaci

between the

certain.

Do you have some kind of voltage tester? That is the real answer. 2 will be hot and one ground. Tape the grounded one white for next time. Don't try "trial and error" the "error" (66% of the trials) will put 120v on the case of your stove.

Go to the panel and look at the breaker, My guess would be blacks are hot.

Better yet, go ahead and test it for your own information. But don't mark what you believe to be the neutral and then bring an electrician in. Let whoever you hire figure it out from scratch or you might be liable if he screws it up based on your marking.

Correct. Never trust anything. The pro you hire shouldn't do so either, but don't go creating a misleading situation.

Identifying the ground conductor with white tape is a violation of the electrical code. Green tape would be appropriate.

keep in mind the third wire in such an arrangement is not the "grounded" conductor (the more technical name for the neutral wire) but rather it is the grounding conductor (i.e.-the green wire in normal cases). In this case the grounding conductor is being also being used as the return path for the small 120V loads.

Since we have to set the "way back" machine to 1993 (NEC) to make a 3 wire plug lets go look at 250-60 in the 93 code. It clearly calls this the groundED conductor.

Don't do anything without a voltmeter.

With a voltmeter... Test voltage between each of the wires. There will be 240v between two of your wires. Those are the hots. There will be 120v between the hots and the third wire. The third wire is the ground. It should be obvious were each wire goes.

If the voltages are not as I described, you have a problem.

It is nearly certain that the two black wires are hot and the red wire is ground; but do not try it without testing.

If you don't know why there are two hots and no neutral, a book on basic electricity is good reading.

Well, $50 and 1 house call from an appliance repair service later, I discovered the problem is that I need a new pair of glasses.

The pro put the new receptacle I had purchased on in a jiffy, but pointed out one little thing: I don't have two black wires and one red one. I have a black wire, a *navy blue* wire, and a red wire. The navy blue wire, according to his voltmeter, was the ground. The red wire, as I thought, was hot.

Thanks for all your responses. Embarrassingly yours, kaci

Geese - I just found an old 1990 J.F. McPartland handbook. Looks ancient! Anyway, it's interesting to read why he said they allowed such an arrangement:

"The reason for allowing these appliances to be grounded by connecting them to the circuit neutral is that the circuit is usually short [no pun there, I think ;-] and the groundED neutral conductor is large enough to provide against it being broken. On such equipment if the neutral were broken, the equipment would usually become inoperative and it would be necessary to have repairs made before operation could be resumed."

Of course, as my luck would probably have had it, about a millisecond after the neutral opened (as the sine wave peaks, of course) is just when I would've dumped the large kettle of water down thru the elements while reaching over to the sink to turn off the faucet :( The nice large wires and the nice large breaker they were on probably helped reveal the fact that now I was THE groundED conductor.

Perion

Yeah, yeah.

BUT the first "test" should be with the POWER OFF.

The test would be to measure the resistance between each of the three wires and a known ground (like from a regular grounded 120 volt outlet.)

The neutral wire should than have some white tape wrapped over the entire visible length of the insulation.

If someone went to the trouble of wrapping some RED tape around one end of the wire, he likely did the same at the other end. Take the cover off the panel and check.

If someone actually put RED tape over the neutral/grounded conductor, he definitely had a screw loose!

| Your points are well taken. I am not against hiring an electrician and | will do so, but in the meantime I still have some curiosity as to how | things work. I was just wondering, assuming the red wire is hot, is | there any way to tell other than trial and error, which of the two | black wires is neutral or ground. I haven't been able to find this | wiring arrangement in anything I've read so far.

If you look inside the panel where the wires run to, that may answer your question. If I were installing such a circuit and had to use wire like that, I would make red be neutral and mark it as white. If red is in fact connected to the neutral neutral bus, this is simpler. But if one of the black wires is connected to the neutral bus, you won't know which is which at the other end, unless it was marked (such as a white tape around one of them). An electrician would probably wire it up once, turn on the power, and measure the voltages. One of the wires would have 120 volts to each of the others, and those others would have 240 volts between them. That would identify the neutral wire, and then he can rewire it correctly, and recheck the voltages to be sure. He might even wrap some white electrical tape around the neutral wire to mark it.

| Identifying the ground conductor with white tape is a violation of the | electrical code. Green tape would be appropriate. | | keep in mind the third wire in such an arrangement is not the "grounded" | conductor (the more technical name for the neutral wire) but rather it is | the grounding conductor (i.e.-the green wire in normal cases). In this case | the grounding conductor is being also being used as the return path for the | small 120V loads.

What you are describing is a 2 wire 240 volt circuit. But electric stoves run on a 3 wire 240/120 volt circuit and have done so since well before the groundING wire was required by code. It was thus the groundED wire back then and that designation would not change.

I have also seen stoves that have the cooktop elements using 120 volts while the oven elements use 240 volts. That's not "small 120V loads". I'm sure 2 of them were on one phase and the other 2 were on the other.

If you find an electric stove that works on a true 2 wire 240 volt circuit made for the USA market, I'd sure love to see that.

So this really is an UNgrounded 3 wire 240/120 volt circuit using the neutral groundED wire as if it were a groundING wire. And the code does grandfather in older installations like this so that, for example, you do not have to re-run the wire to these special cases (e.g. stove) if you do some other major work like replacing an old fuse panel with a modern breaker panel (you would, for example, now have to put AFCI breakers in for bedroom 120 volt 15 and 20 amp circuits).

If such a circuit is attached to a SUBpanel, where neutral and ground are not bonded together, then the neutral wire of this circuit must be connected to the neutral bar. Connecting it to the grounding bar would defeat the purpose of having a separate grounding wire by putting current, and thus some voltage, on the groundING wires in that subpanel.

| "The reason for allowing these appliances to be grounded by connecting them to | the circuit neutral is that the circuit is usually short [no pun there, I think | ;-] and the groundED neutral conductor is large enough to provide against it | being broken. On such equipment if the neutral were broken, the equipment would | usually become inoperative and it would be necessary to have repairs made before | operation could be resumed."

I've seen 2 cases of broken neutral on a stove circuit. In one case a light over the bar was attached to the stove circuit. The light changed in brightness with the variations in heat setting for the stove elements. The stove elements actually did work if enough were turned on. People might not quickly recognize it as "inoperative", but rather, as "operating funny". The fact that this light WAS on the stove circuit helped to see the situation which might have gone unrecognized for a while (because it actually was "operating funny" for a while).

In the 2nd case I saw, the open neutral was in the stove plug itself. Eventually the clock on the stove quit because the magic smoke got out.

| Of course, as my luck would probably have had it, about a millisecond after the | neutral opened (as the sine wave peaks, of course) is just when I would've | dumped the large kettle of water down thru the elements while reaching over to | the sink to turn off the faucet :( The nice large wires and the nice large | breaker they were on probably helped reveal the fact that now I was THE groundED | conductor.

It could have been broken long before. If the stove had 240 volt elements, you might not know. I'd rather have a stove with everything designed for

240 volts, period. One designed to be functional and properly safe on both North American and European electrical systems would do the job. Control circuits can be made for 240 volts, and would need to be in Europe unless a transformer is used (and one might well be to get it to some other voltage for today's digital circuits, anyway).

What you said is correct.

Further along in the thread, Kaci (original post) described the wire colors as: Black, *Navy Blue*, and Red. That seems a bit odd to me. Sounds like someone might have inked out the white conductor for some reason or another and later thought better of it??? I've seen some guys ink out white wires whenever they made them hot for some reason or another instead of taping them. I.e. reversed switch legs, or a X-2 wire in which they use it for a 2 hot and ground config...etc... Anyway in this situation a white or grey neutral I could understand. You would think whoever the last person was that had anything to do with the receptacle should have taped it white.

Pete

Perhaps the guy who chose blue for the neutral was from Europe where this is a standard thing.

If you look at line cords for PC and such that trade in international commerce you will see they are brown (hot) and blue (neutral). The NEC does make a glancing reference to that in 400.22(C) but it says "light" blue.

| Further along in the thread, Kaci (original post) described the wire colors | as: Black, *Navy Blue*, and Red. That seems a bit odd to me. Sounds like | someone might have inked out the white conductor for some reason or another | and later thought better of it??? I've seen some guys ink out white wires | whenever they made them hot for some reason or another instead of taping | them. I.e. reversed switch legs, or a X-2 wire in which they use it for a 2 | hot and ground config...etc... Anyway in this situation a white or grey | neutral I could understand. You would think whoever the last person was

You'd think they would do it right. But just what was right and common practice back in the day when a separate groundING wire was not required? Sounds like someone got hold of some surplus wire originally intended for

3 phase delta uses and decided that the blue was sufficiently unusual for single phase that it would be used as neutral. But were the rules on remarking colors in place back then (whenever then was)?

Yes, my oldest code book is 75 but you were still required to use white wires for grounded legs. The only change I know of was the recent requirement that switch legs in cables shall be reidentified.