4 Way Switch, Light in The Middle?

[Ditch Doc]

Hi all

I'm working on wiring up some lights in my shop. There will be two 3-way switches with a 4 way in between. It's a long way from the panel to the first switch, so I'm looking for a way to cut down on the amount of cable needed while still staying code compliant. I was originally taught that when 4-way switches are used, the light must ALWAYS go on the end of the run. However, looking around the interwebs, I am finding a few diagrams that suggest otherwise. Are these acceptable by NEC??

 

[BigGarage]

Hi all

I'm working on wiring up some lights in my shop. There will be two 3-way switches with a 4 way in between. It's a long way from the panel to the first switch, so I'm looking for a way to cut down on the amount of cable needed while still staying code compliant. I was originally taught that when 4-way switches are used, the light must ALWAYS go on the end of the run. However, looking around the interwebs, I am finding a few diagrams that suggest otherwise. Are these acceptable by NEC??

The lights do not have to be at the end of run. I have two 8' pairs of lights with 3 ways on both ends and a 4 way in the middle.

I consult my handy-dandy $14 electrical book for questions like these and then I do the work.

Dennis

 

[pattenp]

The diagram shown is not an NEC issue.

 

[wyliesdiesels]

The diagram shown is not an NEC issue.

There is one issue with the diagram.

A neutral is required in every switch box now under current code.

In the diagram, the neutral goes directly to the fixture...

 

[larry4406]

There is one issue with the diagram.

A neutral is required in every switch box now under current code.

In the diagram, the neutral goes directly to the fixture...

So do they make 4-wire Romex to achieve this? If so what are the colors? Are the neutrals just wired together doing nothing in the box other then being there and spliced?

What would the neutral be used for? Some fancy automation smart switch?

 

[wyliesdiesels]

Yes, there is NM-b **-2-2 where ** is either #14 or #12.

The neutral is required for switches that need a neutral.

 

[Crazyjake8493]

https://www.homedepot.com/p/Southwire-25-ft-12-2-2-Solid-Romex-SIMpull-CU-NM-B-W-G-Wire-55048421/302321065

As Wylie mentioned.

 

[pattenp]

There is one issue with the diagram.

A neutral is required in every switch box now under current code.

In the diagram, the neutral goes directly to the fixture...

Yeah, I wasn't looking that close at the diagram and was thinking of the light not having to be at the end of the run. Also the requirement of a neutral at the switch box has an exception if there is access to add a neutral later.

 

[ard]

while still staying code compliant.

A neutral is required in every switch box now under current code.

..

So OP....whatcha gonna do?

If you are running these circuits new, easy enough- but if retrofitting existing switches the whole 'code compliant' thing can be a challenge....

 

[larry4406]

What NEC Code cycle (year) did the requirement for a neutral in every switch box go into effect?

What types of 3-way and 4-way switches use a neutral? Smart switches, timers, pilot lights? The normal 3-way and 4-way light switches don't use a neutral.

I'm not a sparky, just trying to learn. The 3-way and 4-way lighting circuits I see on the job (new home construction VA and MD) are simple daisy-chains of 14/3. Usually the switches are in 2 or 3 gang boxes with other switches so maybe that is where the "presence of neutral" comes from. My house from 1987 does not have a neutral present in the various 3-way and 4-way single gang switch locations (Romex wiring, stud and drywall partitions).

I will be wiring some of these 3-way and 4-way lighting circuits soon as part of my barn project. I am in Virginia which is still on the 2014 NEC. It will be inspected.
https://www.mikeholt.com/necadoptionlist.php
https://www.nfpa.org/-/media/Files/...tituteFallingBehingElectricalSafetyReport.pdf

 

[jim111]

Under 2014 NEC you only need one switch location with a neutral in a three or four way set-up, provided the switches are in sight of the entire floor area of the room. That has changed with the 2017 code

 

[dscheidt]

What NEC Code cycle (year) did the requirement for a neutral in every switch box go into effect?

What types of 3-way and 4-way switches use a neutral? Smart switches, timers, pilot lights? The normal 3-way and 4-way light switches don't use a neutral.

2011, I think. The switches that require a neutral are anything that use power; smart, timers, certain dimmers, occupancy and vacancy sensors, plus probably some I can't think of right now.

There are exceptions, if wires can be changed without damaging finishes, you don't need one. That basically means conduit with capacity for more wires.
There's also an exception for rooms with multiple switches, allowing the occupancy sensor to cover the whole room. I'd have to read the code to see what exactly ti says.

 

[rlitman]

Under 2014 NEC you only need one switch location with a neutral in a three or four way set-up, provided the switches are in sight of the entire floor area of the room. That has changed with the 2017 code

Really? The first makes sense, the second does not.

In the traditional 3/4-way switch, no neutral is required.

With smart switches, only ONE switch (in every variation that I've seen) requires a neutral. The other switches either:

1) connect back in a dumb fashion like standard switches (in this scenario, dimming usually can only be performed at the smart switch, unless some sort of powerline communications is used), or

2) use standard switches that are wired either in the usual or a weird way, but regardless, no neutral is required, or

2) connect using a proprietary wiring method (in this scenario, one of the wires is hot, a second is neutral, and the third is used for communication, but none are actually switched by the slave switches).

 

[exranger06]

Yes, there is NM-b **-2-2 where ** is either #14 or #12.

The neutral is required for switches that need a neutral.

There are 2 different kinds of 4 conductor Romex. There is **/2/2, and there is **/4. The **/4 has a black, red, blue, and white wire. The white is a neutral wire, and the black, red, and blue can be used as hot/switched legs.

**/2/2 wire has a black, white, red, and red and white striped wire. The white and the red/white striped wires are both neutrals, although you can color the end black to re-identify it as a hot or switched leg. **/2/2 is typically used to run 2 circuits in one cable. **/4 is the cable I would use, unless you can't find it easily, then just re-identify the red/white wire.

 

[Falcon67]

So OP....whatcha gonna do?

If you are running these circuits new, easy enough- but if retrofitting existing switches the whole 'code compliant' thing can be a challenge....

What I did for the new smart switch in the kitchen was kill off the 3 way. One run abandoned in place, the other changed to using the white neutral as normal and the red+black used for the switch leg. No way to run new wire, so just picked the switch most visible from the normal sight lines for the new decora switch and blanked out the other. The Kasa switches I'm using don't seem to have a real 3 way version. They sell a "three way kit" but when I look at the individual switches in the kit they appear to be regular on/off.

 

[grounded-b]

There is one issue with the diagram.

A neutral is required in every switch box now under current code.

In the diagram, the neutral goes directly to the fixture...

A grounded circuit conductor (neutral) is NOT required at switch boxes fed by a cable assembly, IF the wall, ceiling, floor is exposed on at least one side OR the framing cavity is accessible at the top or bottom.

per NEC art 404.2(C) exception (2)

These wiring diagrams would be OK under those circumstances.

Steve
JW

 

[Ditch Doc]

There is one issue with the diagram.

A neutral is required in every switch box now under current code.

In the diagram, the neutral goes directly to the fixture...

That little detail may have just saved me a lot of work ripping it all out and redoing it. Much appreciated! So... I have been staring at the diagram for a while now. I'm having trouble figuring out how to carry the neutral through each box. The only thing I'm coming up with is running 12/4 cable, using the blue as a traveler and keeping the white a neutral. It seems like that would work, but wouldn't really be practical in this case. I haven't done this setup before, so I may just be overthinking this.

A grounded circuit conductor (neutral) is NOT required at switch boxes fed by a cable assembly, IF the wall, ceiling, floor is exposed on at least one side OR the framing cavity is accessible at the top or bottom.

In this case, all of the cable is exposed.... armored cable secured to plywood walls. It sounds like it may fall under this exception.

So OP....whatcha gonna do?

If the neutral would be a code issue, it looks like the best bet would be to keep the light at the and and just run the extra cable. It would be less expensive than buying a roll of 12/4. If this case falls under the exception, the way shown in the diagram would save cable, money and space.