lazy susan

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butchetsetera

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i attempted to replace 2 pairs of 3-way switches. after removing the pair downstairs, i discovered that it was ran in 2 wire. i changed both switches downstairs and turned on one of the switches to check it. i got a dead short. i don't think i understand how the switching was done all in 2 wire. im going back today to give it another look. it doesnt seem to be the same wiring as using 3 wire. anyone heard of the "lazy susan" 3-ways and how it is run with just 2 wire.
 
This is a scary question to read, especially with (or in spite of) your profile proclaiming you an electrician. This should be simple circuit tracing. If you're really a DIY'er, please distregard this post. I will give you a few hints (I hope I'm not wrong doing this :oops: ):

Here's what you should have seen when you removed the original switches: a black wire from a cable whose white joins other white(s), which should be the switch's common, and both a black and white from another cable, which should be the travelers.

You should have made note of which wire was attached to the darker (common) terminal of each switch, and not the physical placement of each terminal on the switch body. Plus, only remove and replace one switch at a time, like you would spark-plug wires.

The cable type has nothing to do with the electrical connections only the insulation color. Each switch gets 3 wires: one common (one of which is always hot, and the other of which feeds the fixture) and two travelers which interconnect the two switches).

If you have a direct short throwing a switch, it's more likely that you have a bare wire touching a screw (assuming you did not disturb any other connections in the boxes); meaning poor box stuffing. (No grounded circuit conductor should land on a switch.)
 
8) sounds like a "hollywood" 3-way.... (An illegal method to install for reasons I'll mention soon. But stuck with whats in the walls now.)

Lets get straight here... You replaced two 3-way switches, right? There were 3 conductors each on these switches? How old was the original construction wiring?

Other than the obvious unintentional grounding of the switch terminals, you could have done this.... A "hollywood" 3-way, which has a switched hot on one 3-way, and an (illegal) switched neutral on the other. Most of these would have a hot and neutral in each switch box on the switched terminals, and a conductor to the light(s) on the common. Depending on the position of the switches the light would either get a hot and neutral and work, or either 2 hots, or 2 neutrals, and not work. Accidently swapping a wire would easily create a short, or installing a dimmer on this circuit would definitely short though the dimmer.
 
I seem to recall that back in the very old days some of the three ways would switch from top-bottom and others switch side to side?

This along with an illegal switched neutral would be a problem, even if the wires were swapped one for one.
 
Butch, In the rough, they fed both banks of switches with power.only the 2-wire was used for travelers.The nuetral was picked up in the second bank of switches to the light.Not legal at all.As far as tripping, look for the black spot if it was grounded, if not you could of crossed the pairs if multiple circuits are in the box.
Rick
 
RUWired said:
Butch, In the rough, they fed both banks of switches with power.only the 2-wire was used for travelers.The nuetral was picked up in the second bank of switches to the light.Not legal at all.
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Not necessarily true. If both switch locations are on the same circuit, this is okay with non-metallic wiring methods. There will not be a significant enough amount of induction current to matter.

Plus, I have used two runs of 14-2 between 3-way switch locations, one pair as the hot'n'neutral, and the other as the travelers. Feed one switch at one box, and take the leg out of the other.
 
Larry,Both 300.5(I) and 300.3(B) say (where used) the grounded conductor shall be installed in the same cable.
Rick
 
RUWired said:
Larry,Both 300.5(I) and 300.3(B) say (where used) the grounded conductor shall be installed in the same cable.
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Rick 300.5 only applies to underground installations and it also says "or shall be installed in close proximity in the same trench."

As far as 300.3(B) take a look at 300.3(B)(3).

If you use NM with plastic boxes or NM with metal boxes and follow the provisions of 300.20(B) you can run the conductors separately.

I do not think it is good practice or design but it can be done within the rules of the NEC.
 
Bob, 300.3(B)3,and 300.20(B),(single conductor) only pertains to cables having to do with any sort of metal involved.I can't see how any of those two articles can be transposed into nm cables running in a dwelling.Even if they are in nm boxes.
Rick
 
RUWired said:
Bob, 300.3(B)3,and 300.20(B),(single conductor) only pertains to cables having to do with any sort of metal involved.
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Rick I do not agree, I ask that you read 300.3(B)(3) more carefully.

300.3 Conductors.

(B) Conductors of the Same Circuit. All conductors of the same circuit and, where used, the grounded conductor and all equipment grounding conductors and bonding conductors shall be contained within the same raceway, auxiliary gutter, cable tray, cablebus assembly, trench, cable, or cord, unless otherwise permitted in accordance with 300.3(B)(1) through (4).

(3) Nonferrous Wiring Methods.
Conductors in wiring methods with a nonmetallic or other nonmagnetic sheath, where run in different raceways, auxiliary gutters, cable trays, trenches, cables, or cords, shall comply with the provisions of 300.20(B). Conductors in single-conductor Type MI cable with a nonmagnetic sheath shall comply with the provisions of 332.31. Conductors of single-conductor?type MC cable with a nonmagnetic sheath shall comply with the provisions of 330.31, 330.116, and 300.20(B).
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NM has nonmetallic sheath and it is a cable, if it is used with plastic boxes 300.20(B) is not applicable at all.

If we simplify 300.3(B)(3) to just reference NM it would look like this.

(3) Nonferrous Wiring Methods. Conductors in wiring methods with a nonmetallic sheath, where run in different cables, shall comply with the provisions of 300.20(B).
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I have not changed the meaning of 300.3(B)(3) at all, I have only removed the references to other cable and raceway types for clarity.

Remember Charlie's rules of reading. :)

The code does not say what you remember it to say.

The code says what it says.
 
Does Larry use plastic boxes, or otherwise snip the barrier between metal knockouts to comply with the provisions of 300.20(B) ?
 
ramsy said:
Does Larry use plastic boxes, or otherwise snip the barrier between metal knockouts to comply with the provisions of 300.20(B) ?
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He does if if wants to meet the code.

I believe he said;

If both switch locations are on the same circuit, this is okay with non-metallic wiring methods.
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Sounds like NM with plastic boxes.
 
ramsy said:
Does Larry use plastic boxes, or otherwise snip the barrier between metal knockouts to comply with the provisions of 300.20(B) ?
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Let's see.

"Hey, Larry! Do you 'use plastic boxes, or otherwise snip the barrier between metal knockouts to comply with the provisions of 300.20(B)'?"

"Why, yes. Yes, I do."

Hey, Ramsey, he does. :D


iwire said:
I believe he said;

If both switch locations are on the same circuit, this is okay with non-metallic wiring methods.
Click to expand...

Sounds like NM with plastic boxes.
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I agree. That's what it sounds like to me, too. :D
 
RUWired said:
Bob,I don't buy 300.3(B)3,
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What don't you buy? :)

That the code allows running conductors of the same circuit in separate NM cables?

I never said I think its a good idea but can you point to something in 300.3(B)(3) that I have misstated?

RUWired said:
But i would buy 200.7(C)1.for a small price. :D
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?

We could still meet that requirement in separate cables.
 
well ,what i don't see is how you can use 300.3(B)3 to support the use of this wiring method.This article is only referring to single" conductors".The reason for me saying that is that it refers you to 300.20(B)

300.20(B) Individual Conductors Where a single conductor carrying alternating current passes through metal with magnetic properties, the inductive effect shall be minimized by (1) cutting slots in the metal between the individual holes through which the individual conductors pass or (2) passing all the conductors in the circuit through an insulating wall sufficiently large for all of the conductors of the circuit.
In the case of nm cable ,there are more than two conductors.I believe 200.7(C)1 would support the use of this wiring method.
Rick
 
Actually 200.7(C)1 would'nt work either because of 300.3(B).That would only work if the grounded conductor was within the cable.
Rick
 
yeah, i got the 3-ways done. when i posted the question, i couldn't wait for an answer. I had to just get it done. for some reason, 3-way swithes wouldn't work. I had to use what they had installed before (4-ways) using only 3 terminals.
 
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