In my electrical training it was called a South Dakota 3-way. I'm from North Dakota.Forty some years ago I lived in a home that had a Tennessee 1 wire 3 way (rope pull chain) at the top and bottom of the basement stairs for the pull chain at the bottom. I want to say it was several pull chains in the basement connected together to the same 3 way rope.
One day my brother tried to use the pull chain rope at the top of the stairs to swing down to the concrete floor below..
Think he lost few baby teeth on that one.
Just wondering what about a grounded conductor required at each switch box controlling a lighting load?
Or the switch is required to have an EG 250.4(A)(3)?
Good insight. My first nec book is from 1978. I've been a pipe and wire guy for a very long time. RF switches are something that I have hesitated feeling comfortable with. Especially when using them to replace a hardwired switch in a 3 or 4 way application. I've recently overcome my fears when I started using the Caseta product. Ten years is a pretty good lifespan and they can be easily replaced if they go bad. Looking at the questionable quality of some of the wiring devices on the market nowadays, I think the Caseta, in contrast, is a solid product. I'm not yet sold on the addressable light bulbs...Two viewpoints:
---Can not beat the reliability of hardwired switching.
---Can not beat the flexibility of RF switching.
There are many other trade offs when considering the options we have. I use both, depends on the situation.