NEC 2020 404.2(C) Neutrals in Switch Boxes with Example and New 2020 Exceptions

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[RobertLeBlancPhoto]

Having a neutral inside the switch box is a lifesaver when electronic switches are desired.

[farmerjim-fat-man-do]

electrician for 30 years, master for 20. Most of my work is in the industrial environment but have wired many homes back before this code change. This code change applies to any application but I don’t see a lot of switch legs in commercial / industrial applications. The exception for conduit is the work around when they are used. In my opinion, requiring a grounded conductor on a switch leg is another example of the electrical manufacturers influencing the code authors. Same as Arc fault receptacles/ breakers. Just ‘cause manufacturers can build it doesn’t mean it should be written into code. If electronic light control is specified in a home then yes, install the grounded conductor. Requiring this for every switch leg changes the way us old electricians work and think about residential wiring. Plus it’s a waste of resources. Now I have to change the way I route my branch circuits which requires more cable or to comply with this code or use a 3 conductor cable for the switch leg where a 2 conductor cable worked fine since electricity was installed in homes. Thats my rant for the day…stepping off my soap box now.

[GregSr]

Great demo. Seeing is believing. My house was built in 1990. I ran into this exact situation last week. I wanted to install a smart dimming switch in the master bathroom. Opened the switch box up only to discover NO neutral wire. The smart switch requires a neutral connection. In the switch box, the white wire was hot and the black wire was the load. The bare copper ground wire was not connected to anything. Luckily, about 18 inches away was a normal wall outlet. I snaked a neutral wire from there over to the switch box. Bingo! The new smart switch is working as it should.

[tuckernance]

I recently attempted to "quickly" help out my brother by installing a new dining room light and fixing a dimmer-switch three-way combo that had been broken for years. Well, that quick job turned into a full day job when I realized the wiring in 1973 was very different than what I learned on. This was the very situation I encountered with his setup. I ultimately had to get out my tracer and map each conductor out to figure out what was going on. That was a fun little learning experience.

[rswyltk]

Neutrals are required for a vast majority of Smart Switches. I just installed all Smart Switches in my vacation house that was built in 1971. I was pleasantly surprised to find neutral wires in all my switch boxes.

[oUncEblUnt]

your channel is gold. Thank you for going into the minor details, saves us decades.

[webluke]

So if you're doing a new installation or have the finished work off it will save you just to run your feed into the switch. More people will want "smart" things added to their house and this change just helps make sure that it can be added without pulling new wire. I also don't see this as just a way to keep code writers in a job, this is more of them catching up to the demand for new switches and fixtures.

[dallasconger]

Regardless if the power is at the light it could be solved with a 3 wire to the switch box. Black/red for the switches hot and the neutral wire nutted off for future smart switches in a remodel that is.
Power to the switch box in new construction.
I use the big single gang boxes anywhere I can. They’re not that much more in cost.

[lelandlewis]

This reminds me of automotive wiring. All wires are in the main harnesses for all accessories so that many accessories can be dealer or aftermarket installed after delivery of the vehicle or at a future time. Volvo was doing this back in the 80s to save time and money manufacturing vehicles; they had standard features on each model, such as a DL had windup windows, a carbureted engine, steel rims and nothing fancy. Cruise control, radios, air conditioning, trailer towing packages, etc., were dealer installed if the customer wanted it. GL models all had power windows, heated leather seats, fuel injection, aluminium wheels, etc., but stereos, speakers, AC, etc. were dealer installed.

This code is basically doing the same thing, having the wiring in place for future upgrades, thereby saving time and money if and when they are done. I do this in my own house, install wiring and water/sewer runs for things I may afford later on.

[samuelt]

This isn't just about installing a regular switch controlling a device; it's about the future possibility of a "electrical control device" (timer/switch; dimmer/switch, etc) being installed in the same box. These require more than than a ordinary switch loop.

[gn]

I always preferred running the power to the switches and just a switch leg up to the light. Pulling light fixtures down when trouble shooting is a pain in the neck. I remember working on old houses with the Knob and Tube wiring. They switched the neutral and there was no ground. You had to run a wire from a pipe or the panel to use with your Wiggy so you could identify the hot and neutral. The good old days.

[Tolohtony]

Just in time. I'm wiring my basement bathroom and had it wired pre-2020. Thanks!

[markt]

This is the video I requested. Thank you for posting so quickly. Now I going to wire accordingly and install my smart dimmer switches. Because of all of your help I may have rename Alexa to Bill. Thank you again and hope YouTube will reload all of your videos and subscribers. Also, I am changing all outlets and switches to Leviton.

[ronaldoleksy]

Makes sense when you are using electronic control. I remember be taught about switch loops as in your example. I have ran I to switch loops an electronic dimmer. We decided not to use electronic device. God video

[ClTlZEN_X]

I remember my first switch loop as if it was yesterday. Never seen anything like it before. Now those retros are no challenge.

[Litephaze]

I LOVE that your switch/apparatus screws are vertical!!! I have a major pet peeve about that, LOL!

[emmanuelny]

Hello Bill Well made video no body can explain it better then you; I learned so much because of your videos and I love all your videos, sorry about what happened to your channel I hope you get all your subscribers back don’t give up best wishes and all best my friend.

[johnhill]

So then why not just bring the power to the switch box and run the cable to the load? 12/2 w ground is cheaper than 12/3 with ground.

[matthewtuel]

It's good to know that my basement re-wiring follows the 2020 NEC. I wired exactly as shown with a 14/3 to the switch box and nutted the white for future use. The power comes in through the light box as it did originally. I am wondering if that is allowed or if I should have "rectified" the situation given that it's an unfinished basement and running new wires is less of a chore that it otherwise would be.

[raymond]

It was more than helpful..it was a very thoughtful lesson with clear clarity.