I built a deck on the back of my house last year and installed a new breaker and a handful of outdoor electrical outlets. I wanted one outdoor outlet to be switchable via a smart outlet, but my smart outlets aren't waterproof so it had to be inside the house.

As a solution, I installed a GFCI next to my breaker panel. I have my unswitched outlets coming off the load side of the GFCI so they are protected. For the switched outlet, I installed a plug onto the end of the UF wire run so I could plug it into my smart outlet.

This is the part that seems iffy. I think I'm good on bend radius and wire support, it's not subject to continuous flexing and it's relatively protected from damage due to the remote location of the panel (although I could protect it further). It just doesn't quite feel right to have a permanently-installed circuit plugged into an outlet, despite being a clever solution to my problem.

I'm using a 15A non-AFCI/GFCI breaker and 12 AWG UF wire. I ran 12 in case I ever wanted to upgrade the circuit to 20A, but my smart outlet is only rated for 15A anyway.

Is there anything in the NEC that prohibits this? I have access to a full copy of NFPA-70 2014 and would like specific references.

I'm willing to change whatever I need to be code-compliant, but I still want to be able to be able to switch my outdoor outlet via some sort of smart-home device.

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    Have you considered using a smart relay module mounted in a junction box instead of a plug-in style smart plug? You could feed its input of the load side of the current GFCI, and the output would go a standard outlet, which would effectively turn it into a smart outlet. Something like this for example would work: amazon.com/dp/B07RQ866JJ – Nate S. Jul 1 '19 at 23:34
  • Yeah, can you get a hard-wired smart relay for your system of choice? – ThreePhaseEel Jul 1 '19 at 23:45
  • I haven't found a suitable smart relay that is UL Listed and made by a reputable manufacturer. The Shelly switch that @NateStrickland suggested isn't directly compatible with major smart-home systems (Alexa, Google, etc). Although, I could simply buy a box-mounted smart light switch and it would work effectively the same. – Dan A. Jul 2 '19 at 14:36
  • @DanA., that used to be true that the Shelly ones didn't support Alexa/Google, but they recently added that, and they are UL listed, so I think it might meet your requirements. For example, with this one channel one, they explicitly call out Alexa annd Google Home support in the product description: amazon.com/SHELLY-Wireless-Automation-Android-Application/dp/…. But you're right, a smart light switch of your choice would work just as well. – Nate S. Jul 2 '19 at 15:56
  • Thanks for the recommendation! – Dan A. Jul 3 '19 at 20:00

It does violate the NEC (assuming that you are in the US and the NEC applies to you). UF cable is not designed to connect to portable cord devices, portable cord devices are not designed to accept UF cable. Article 110.3(B) states: "Listed or labeled equipment shall be installed and used in accordance with any instructions included in the listing or labeling." You will not find any instructions with the listing or labeling saying you can do this, ergo you cannot.


I agree, this is "nope".

The way I would handle this - first, I'd use metal boxes because I'm lazy about running ground wires.

I'd start by removing the current box. I'd knock out the highest 1/2" or 3/4" knockout and fit an EMT spacer to connect to a 4-11/16" square steel box. We'll need the room. Fit a steel cover that provides 2 Decora. One slot gets the GFCI outlet. The other slot gets a 15A inlet.

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Both cables to outside terminate in the box. I'm moving the box upward to create some slack so you can deal with codevio's at the window entrance.

The cable you want switched goes to the inlet. The cable that is not switched goes to the GFCI's LOAD terminals. The GFCI LINE terminals go to white and black wires, which run through to the panel to the breaker and neutral bar.

Then you plug the smart switch into the GFCI. Then you use a 1' long extension cord to go from the smart switch to the inlet.

The grounds for the inlet and cables get pigtailed to the ground screw in the box. The box and the close nipple carry ground to the service panel and outlet.

That cable near the window is vulnerable to physical damage. It should be folded down more tight to the wall, and guarded by something, not least so the window-opening mechanism can operate without endangering the cable.

  • Accepting J. Raefield's answer since it more directly addresses the code question, but this is a good suggestion. I'll probably end up going the smart relay/switch route as mentioned by @NateStrickland, but will incorporate part of this suggestion as well. – Dan A. Jul 3 '19 at 19:59
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    @DanA. I agree. Be careful with relay modules to get a UL listed one; CE is a mark of shame (if they had a proper mark, they'd use it instead). Also don't follow my "metal box" idea with WiFi modules unless it mounts in a knockout somehow (in which case metal is ideal). – Harper - Reinstate Monica Jul 3 '19 at 20:37
  • I would have run those wires by the window through the rim joist 12" straight up. Would have been a much more tidy solution. – FreeMan Dec 2 '20 at 19:32
  • The exterior of my home is brick, so drilling through the rim joist also means drilling through the brick. That's not difficult with a masonry bit, but I prefer to poke as few holes in the brick as possible. In any case, I'm currently in the process of finishing the basement, and permanently covering up this window anyway. – Dan A. Dec 2 '20 at 23:32

My actual solution

I fixed this a while ago but never came back to update the post. I ended up getting a Wemo smart light switch (since I already have other Wemo devices) and wired that to the load side of my GFCI to control my outside outlet. Looks nice and works great!

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A plug-in smart outlet is the wrong device for this

Instead, what you want is a smart relay, or smart light switch. That way, you can wire directly off the load side of your GFCI, and will not need a creative solution to connect the output of a NEMA 5-15 socket into your fixed building wiring.

Option 1: UL Listed Smart Relay

Although specific product recommendations are off-topic for this site, I'm going to link to one anyway, since as far as I know, there's only one smart relay module that's both UL listed and compatible with modern smart home systems (Alexa/Google Home): The Shelly 2.5. Note that they currently sell them in both UL listed and non-listed versions -- if you're in the US, you need the UL listing to be legal and pass inspection; if you're in Europe, you can use either. These are designed to mount in a junction box or on a DIN rail.

Shelly 2.5

Option 2: Smart Light Switch

Here, you have more options from all the usual suspects (Lutron, GE, etc). Note that you'll still want to look for a UL listing. Replace the junction box your GFCI is in with a 2-gang one, and add a smart switch next to the GFCI. Wire the line side of the smart switch to the load side of the GFCI, and the load side of the smart switch to the UF cable feeding your outdoor outlet. An advantage of this setup is that you can manually operate the switch even if your wifi goes down.

GE Smart Switch

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