Wire a 4-way light circuit with 14/2

HooKooDooKu

So what would be wrong with wiring a 4-way light circuit using nothing but 14/2 as shown in the diagram below.

Is there something against code with your hot comming from one direction and your neutral from another?

For the extra black wire between "Power" and "Light 1" and the extra white wire from "Light 3" and the last "3-way", couldn't you mark them with something green and connect both ends to ground?

I know others have complained when I've presented this, and I must admit that it likely uses more wire than just using 14/3 if you only have 1 or 2 lights you want to power.

But in my case, I basically want to wire a set of lights to light the Path from the cars to the basement steps. I want to be able to switch the lights at the steps or either side of the two cars. So in essence, I've got a path of lights and an parallel path of 3-way/4-way switches. So you are going to effectively be running two parallel circuits any way. It's just a matter of running an extra 14/2 to connect the lights to the last 3-way so that you can substitute 14/3 for 14/2 on the run of switches.

BTW, note the white wires marked with black on the switch run.

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AllanJ

The neutral must accompany the hot, except where (raw) hot goes off to a switch and switched hot comes back the same way. The latter situation is called a switch loop.

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Speedy Petey

And yet another thread with this question.


Yes. You have been told multiple times, on multiple forums, from multiple people, that this is a code violation and not a good idea in general.

HooKooDooKu

Couldn't remember if I asked the question HERE, or not (I had asked in other forums as well, but never included a diagram for the loop idea).


That said, no one else shot the idea down better than AllenJ did. Others did say it was a code violation, but I don't remember anyone saying WHY like AllenJ did (they just said it was a code violation... at least the responses I saw).

That pretty much leave the only legal way to wire the circuit with all 14/2 would be to run 14/2 from the last 3-way back to the power source. Doing so basically means you have three runs of 14/2 rather than just one run of 14/3 (the switch loop) and one run of 14/2 (the lights).

Hey, in the end, the questions have served their purpose... teaching me a little bit more about the right way to wire my house. In this case, it just took three questions before I got the simple answer to "WHY". And that WHY has taught me more beyond this simple question.

frenchelectrican

The way you have the drawing that does not meet the code at all.

I know few members been mentioning to you the direct answer and some of us are legit electrician by trade and we know what is legit and what not.

Therefore just ditch that drawing and come up something more correct and for myself I will run like this power - switch - switch - switch - luminaires.



Merci,Marc

nap

well, one thing that usually doesn't make sense is to have two pathways to a light anyway. How would you end up with just the neut going to the lights like that?

there really isn't anyway to avoid running the neut with the hots through the switches. Simple run 1-14/2 to the first switch, then you are going to have to run either 1-14/3 or 2-14/2 to each of the following switches and a 14/2 from the last switch to the lights and then to each subsequent light.

you already have the 2 conductors (hot and neut) running from the source to the first switch and the same from the switch to the light. what you need from switch to switch would be 2 travellers, the neut and the ground. So, you either use 14/3 or 2-14/2 with a spare conductor with the 2- 14/2 between each switch. If it were me, I would much prefer it in 14/3 but I do not believe there will be a code compliance problem with the 2-14/2.

HooKooDooKu

Do you mean logically, or according to code.

The logic here would be you deliver a hot and neutral from breaker to the 1st 3-way switch. The simple part of the explination is using 14/2 for the travellers. Once you've wired all the 3-way/4-way, you have your neutral at the 1st 3-way and your hot at the last 3-way. To wire the lights, you just need one conductor to get the hot to the last light, and one conductor to get the neutral to the 1st light. Then you just use 14/2 to connect all the light's hot and neutral.

The electrical path is throught the switches, then "backwards" through the lights, and back to the neutral at the 1st switch.

But like I said, as I understand it, this will not meet code because you can't have hot and neutral in a "loop", they must be run together. (In this case, they diverge at the 1st switch and don't get back together until the lights).

nap

code due to that is where your hot circuit goes.

but logistically as well since in your situation, what sense would it make to run a wire from the source to the first light shown? That means you have 2 paths to the lights which is unusual and often would result in a lot of wasted wire.





I understand exactly what you are proposing.

the way you have it, you have no neutral to the switches at all from what I see. It;s not diverging at the first switch that is the problem,it is as simple as it would not be carried with the switch leg from the last switch to light #3.

So, either use one 14/3 or 2 runs of 14/2 between the switches and all will be well.

busman

Actually, it is legal under some very specific conditions outlined in an exception in the NEC. I won't say what. I will say that anyone who does this is a HACK. JMHO.

Mark

Speedy Petey

Yes, there are exceptions, but none apply to this situation.

HooKooDooKu

First of all, let me point out that I have made the decision that this circuit will be wired with 14/3. So any other discussion in this thread is just academic.


So... isn't that basically the case in a switch loop... you have a hot going to a switch and a hot coming back from the switch, with no neutral anywhere near the switch? The only difference from the point of view of the switches is that I have a line of them rather than a single one.

Of course the criitical difference is that when you're finished with a switch loop, your hot returns back to where it diverged from the neutral. In this case, the hot never returns to where it left the neutral.


I've been told in other forums where a similar question was asked that 2 runs of 14/2 woudn't be allowed. I've been left with the impression that code requires all the conductors of a circuit to either be in the same sheath or same raceway (excluding switch loops).

Wouldn't that be like trying to fix my single pole sub-panel powered by 10-2 by running a second 10-2 for the other leg? I have again been left with the impression that code would not allow a sub-panel to be fed by two sheaths of NM cable (one leg in one sheath and the other leg in the 2nd sheat). Of course that's unless both sheaths have been placed in protective conduit less than 10' long with no more than one junction box... what a minute, I'm getting the discussions cross connected.

busman

Well, the code is permissive, so what code section prohibits it (as long as it's a non-metallic wiring method with non-metallic boxes and framing)?

Respectfully,

Mark

HooKooDooKu

For a moment, let's pretend there isn't a code violation for the hot and neutral taking divergent paths. Why would this be a HACK?... Other than the fact it is a-typical?

For running a standard circuit like this, you already have to run the 14/2 from the power source to all the lights, and you have to make a wire run through all the switches. What this circuit does is trade the additional work and expense of running an extra 14/2 to connect the last switch to the last light at a savings of using 14/2 over 14/3 AND saves the work of connecting all the neutrals along the path of the switches. You also make the overall electrical path shorter (i.e. less wire resistance).

secutanudu

I always prefer to have a neutral in switch boxes anyway. Even if your original drawing was to code, it still is not practical. If you EVER want to put a timer, motion sensor, pilot light, etc in this box, they require a neutral. Or, what if you decide you want an outlet nearby, now you have a neutral to tap into.

If you are running wires anyway, it makes things easier to change and expand if you have neutrals in your switch boxes. And in residential wiring, the runs are never long enough to add that much cost for the extra wire.

Unless you're talking about a very long run...the increase in resistance is pretty trivial.

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Andrew

Speedy Petey

OK, 300.3(B)(3) says it is allowed if the provisions of 300.20(B) are met.
The first line in 300.20(B) is:

"300.20(B) Individual Conductors. Where a single conductor carrying alternating current passes through metal with magnetic properties,............."

The first few words immediately disallow muli-conductor NM cable.