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Hi there - I am in need of a little help. I am wiring six lights in three different rooms (bedroom, hallway, office) with power that feeds from a common source through a primary junction box. The four hallway lights are on a 3-way switch. The other two rooms are single pole. Your help would be greatly appreciated to make sure I make all the connections correctly. If any of the connections that I've drawn so far are incorrect, please let me know.

In the attached diagram, the yellow line indicates white wire.

Thank you!
 

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Hope this is legible. Note this is not code compliant as there are no neutrals at the switches.
At the three ways the black wire goes on the COMMON screw.

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You didn't say where you are located, but in the US, current electrical code requires a neutral wire be run to the switch boxes. This is in case you ever install a smart switch that requires a neutral connection. With a dumb switch, it won't be connected, but still has to be there. So you'll need 14-3 from the wiring junction boxes to the switch boxes.
 

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Discussion Starter · #5 ·
Thanks for the help!

I was not aware of the code requirement about 14/3 wire to switch boxes, but that makes sense. I live in Washington State. I installed new wiring into a new garage last year and that was not flagged by the inspector, but perhaps it's still a good practice. Does that apply only when you use the neutral wire as hot?
 

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Thanks for the help!

I was not aware of the code requirement about 14/3 wire to switch boxes, but that makes sense. I live in Washington State. I installed new wiring into a new garage last year and that was not flagged by the inspector, but perhaps it's still a good practice. Does that apply only when you use the neutral wire as hot?
When you do that, you will no longer be using the neutral as a hot... you'll provide the proper number of other colors and the loop feed for a switch will not be white anymore.... well, not under most circumstances... a person could run two cables to a switch box and still use one of the whites for a hot leg of a switch. That won't be the norm.
 

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When you do that, you will no longer be using the neutral as a hot.
You never use the neutral as hot. Sometimes you use the white wire as a hot but it not a neutral when used as a hot.
 

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Neutral at all switch locations is in the 2020 NEC.
Neutral at most switch locations is in the 2011 NEC.

OP may dodge a bullet on the *far* 3-way switch: NEC'17 404.2(C) Where multiple switch locations control the same lighting load such that the entire floor area of the room or space is visible from the single or combined switch locations, the [neutral] shall only be required at one location.



I don't think any municipality had adopted the 2020 code yet.
Massachusetts has.
 

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At the three ways the black wire goes on the COMMON screw.
Small detail. You must use white preferentially for always-hot. That is...

  • If neutral is not present in the cable, and
  • you are re-marking the white wire to be used as a hot, and
  • always-hot IS present in the cable....
... Then, you MUST use the white wire as always-hot.

This is to make it easier to detect that someone has reused white as a hot wire. The problem is, if someone uses white as switched-hot, and the switch is off, then the person will measure black hot and white not-hot, and assume something :) This requirement assures the person always detects hot on white.

NEC 200.7(C)(1): The use of [white] insulation for a [hot] is permitted only... (1) If part of a cable with insulation permanently re-identified to indicate its use as a [hot]. If used for single-pole, 3-way or 4-way switch loops, the re-identified [white] conductor shall be used only for the supply to the switch, not as a return conductor from the switch to the outlet.

Re-identified means you must put colored tape on it (well, not gray, white or green) everywhere it's accessible (i.e. at the ends).

So, in your 3-way section, since you're carrying always-hot to the far 3-way, it's gotta be on white. The other two are travelers obviously.
 

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Neutral at most switch locations is in the 2011 NEC.

OP may dodge a bullet on the *far* 3-way switch: NEC'17 404.2(C) Where multiple switch locations control the same lighting load such that the entire floor area of the room or space is visible from the single or combined switch locations, the [neutral] shall only be required at one location.





Massachusetts has.
Neutrals are not required at switches for non lighting loads such as switched receptacles or fans.
 

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Looks good! I prefer wiring the 3-way switches like you have them. I always want the white wire of an NM cable switch loop to be the hot wire, even on a 3-way hookup when possible.

As you have learned, there are different ways to do that and still be code compliant. Tip: The polarity of the travelers makes no difference at all.

It gets furthermore confusing when you have to comply with the new code about having a neutral at some switch locations. If I were you, I wouldn't worry about that just now.
 

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Thanks so much for the help. Can you review this diagram again to make sure I have everything correct?
Looks super good, except for wire markings.

It's mandatory to mark the white wires a color. NEC 200.7(C)(1). Since they're used as always-hot, I recommend black. (also everybody has black electrical tape lol). Shrinkwrap or paint would also do, but who has that?

Optionally... if you are willing to exchange a little personal time for a much more maintainable system, I recommend marking *many more* wires so color defines function. To wit:

- Black for always-hot
- Red for switched-hot (e.g. to lamp)
- Yellow for both 3-way travelers (no need to tell them apart) - they are on the brass screws...

Everything becomes easy mode. Hook up the devices, then just nut all wires by color - reds together, whites together etc.

The most important ones to mark are 3-way travelers... when you see 2 wires in the same cable marked yellow, you instantly know what that is. As opposed to yet another red, black or white in the spaghetti and having to head-scratch to figure out what it all does.
 

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Using white as hot only applies to the loop to and from the fixture in a switch loop, not between the switches.
Hmm, but as written it seems like it could apply to both 3-way switches. The far 3-way switch *is* in a loop after all. I'd be grateful to see any code cite you can use to support it.
 

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The reason for the code, as was told to me, is so that you do not have a fixture connecting to two white wires. That would be confusing even though you are supposed to mark the hot white. That is not really an issue at a switch.
 
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