Have a 3-way circuit [upstairs & downstairs residential] controlling two RAB LED flood lights on back of residence. Building barn and need to add two more LED floods and wire up so that all four lights can be turned on/off from the barn [all new wiring/circuits not yet installed] or from the three way inside the residence. The existing floods each have a white wire and a black wire run to the lights. Hoping to add the new lights to this circuit and use RF switch at barn to communicate with RF switch [dimmer maybe] in the house.

Was told this could be accomplished by replacing one of the 3-ways with a RF switch [dimmer apparently] and installing a remote transmitter switch at the barn. I went to my local name brand electrical store and wrote down what they recommended. Pico wireless control and Caseta Wireless Dimmer. I was surprised because I had read online that the Lutron switches are only effective for maybe 30 ft. The Lutron rep. confirmed the 30 feet report. He said they do not have a solution for my 88' span with one stucco house wall and one 2x6 barn wall to transmit through.

Two questions:
1.) Am I correct in how the 3-way circuit could be made to work with RF switching.; and
2.) Is there reliable RF switching available for distances up to 90' and going through walls as described?

All work to be done by a licensed electrician. I'm just trying to understand what's possible.
Thanks in advance to any willing to help an old horseman keep his wife safe and happy after dark. -

 

Actuation from 2 separate devices in a 2-wire circuit is what makes a "3-way switch". If you have a SPST switching device that can be remote controlled, call it whatever you like; "3-way" simply refers to a switch with 3 wires connected to it to get that actuation from 2 separate devices. It's a "coloquialism". (A "4-way" uses two "3-way"s AND a "4-way"- which gets FOUR wires connected to it)

What you really want to know though is: Yes! Unfortunately, I can't just come up with a manufacturer name and part number off the top of my head, but I've installed them. Leviton is whose catalog I'd be looking at, and I've used the old X-10 stuff many times as well.

 

Look at some quality Z-wave switches like Leviton, GE, HomeSeer, Cooper, and Enerwave to mention a few and a cheap SmartThings Hub. You can get range extenders if you have issues but I doubt you will. Bonus to this setup is you will have control via a smartphone app as well.

 

Actuation from 2 separate devices in a 2-wire circuit is what makes a "3-way switch"

It is in the USA, but not in the UK (at least). Here, 3-way means you have 3 switches each able to turn on/off a common load. We don't know where the TS is based.