Taping in a smart switch into another switch

[Eddy100]

I have a two gang electrical switch box, with one blank switch, and one normal switch that controls a light.

I want to place a smart scene switch in the blank gang and be powered off the neighboring switch. The smart scene switch can trigger scenes (which I need) , though can also control one load. The company says the load is optional and you can just "wire it using power and cap off the load wire".

Smart Light Switch Wi-Fi Scene Controller | TOPGREENER

The TOPGREENER TGWFSC8 smart light switch is a WiFi scene controller that allows you to program custom scenes to manual push-buttons.

topgreener.com

The smart switch has Load, Hot , Neutral, & Tether (tether for 3 way switches).

To confirm, all I have to do is just wire in the hot into the same hot wirenut the neighboring switch is connected to . And then also wire the neutral to the same neutral nut the neighboring switch is in, and that should be fine? (and then ground obviously)

I know this all probably seems very obvious but just a bit cautious as I've never done something without an actual wiring diagram.

 

[wwhitney]

So if this smart scene switch isn't going to have anything connected to its "Load" terminal, do you have other smart switches already installed, which this smart scene switch is going to talk to?

If so, then yes you just need to provide it with constant hot and a neutral. If you have constant hot and neutral in your switch box, that works. Switch boxes may not have the neutral circuit conductor present, but it sounds like your does. Switch boxes also may not have any constant hots, e.g. if the box holds only a 3-way or 4-way switch (other than the first 3-way).

Cheers, Wayne

P.S. On the off chance you have more than one branch circuit present in your switch box (i.e. you need to shut off more than one breaker to kill all the power going into the box), then the different circuits' neutrals should not be intermixed. And you should be sure to use a neutral and a constant hot that are from the same circuit.

 

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[Eddy100]

Thanks! Yeah the smart switch has Wifi and connects directly to the router/internet. From the internet it will trigger Alexa/Smart-things routines. Ideally I would use a battery powered switch (similar in concept to a Lutron Pico remote) that connects to a hub to trigger routines- but amazingly that doesn't exist outside of ZigBee.

The other switch in the gang is a three way. Crossing fingers it's the always hot side.

I actually simplified my situation slightly, it's a 3 way gang with 2 3 way switches, and one blank. I suspect I should be able to consolidate the two 3 way switches into one, and then turn the other 3 way switch into a always hot connection. Cross that bridge if it comes.

 

[wwhitney]

The other switch in the gang is a three way. Crossing fingers it's the always hot side.

You'll want to thoroughly trace out/document the branch circuit connectivity before proceeding. But if there's a bundle of neutral conductors in the box, good chance that at least one of the two 3-ways is at the supply end of the circuit and thus connected to a constant hot.

Cheers, Wayne

 

[Eddy100]

Good news is the box is the always hot side of the 3 way. The bad news it's a very tight fit with three total smart switches . I have two three-way switches in that box, that really only need to be one switch.

I looked at a wiring diagram online of a three-way switch, and I am pretty sure this is how I would consolidate the switches.
1. On the always hot side, remove one of the 3 way switches and cap off every wire.
2. On the not always hot side, remove the same 3 way switch, and cap off every wire except the load. Place the load into the same wire-nut as the load of the other three way switch connected to the one I didn't remove in Step #1.

^Is this accurate?

 

[wwhitney]

So you've got two different sets of travelers between two boxes, each of which currently has two different 3-way switches in them? Then what you propose will work fine if the two sets of travelers are supplied from the same circuit and their loads are already using a common neutral, which should mean that the two sets of travelers follow the same physical path from box to box.

A more comprehensive answer would require you to draw out a diagram of the box showing every cable coming into it, every device in the box, how all the wires within the box are connected, and your understanding of what the other end of each of the cables goes to.

Cheers, Wayne

PS On step 2, often the 3-way common terminal at the load end will just have a single load wire connected to it. In which case you'd need to add a pigtail to a wire connector to the now two loads you want to control.