So you want an automated hardwired light switch, but you’re not sure where to start, and you need 2 switches to control the same light. Well you’re in the right place for a 3-way. The most common wiring requirements of any hardwired automated 3-way light switch is a neutral wire and a traveler. Yes, there are a few…(read very, very, very few) switches that don’t require a neutral, but those will limit you to incandescent only. For those of us using LED, Fluorescent or some other energy efficient bulbs under 20w a neutral is REQUIRED!
So what does this look like?
This is a diagram of a 3-way switch with the neutral run directly to the light. This is not good for automated hardwired light switchs and i would HIGHLY recommend that if you want to automate the light, contact an electrician and have them pull a neutral for you. It’s not as expensive as you think and will save you lots of frustration.
This is a diagram of a 3-way switch with a neutral. The black “hot” connection is broken to turn the light on/off, the white “neutral” connection completes the circuit and the red “traveler” connected the 2 switches allowing either switch to control the on/off state. The bare (hopefully) solid copper wire is the ground. It protects from static build up and from electrical insulation failure, in short it’s only job is to make your home safer. If this is what you see when you remove your wall plate you are a go for hardwired automated light switchs. YAY!
This is a diagram of what you’re automated hardwired 3-way light switch setup should generally look like when you are done. It is very important to know which of your old switches are handling Primary or Auxiliary function and the function of each wire. Getting this wrong can cause the automated switch not to work and can even trip a circuit breaker. Follow your brands wiring diagram completely. Different manufactures handle 3-ways differently. Also Yes there will be some slight differences on weather or not to pigtail (a short wire that leads from the switch to the yellow caps) the load and/or line but your ground and neutral should ALWAYS be pigtailed.
Ultimately, if any of this makes you feel uncomfortable or the wiring diagrams makes your eyes cross… CALL YOUR LOCAL ELECTRICIAN! They are there to help! Bad wiring causes fires and other glitchy weirdness you don’t want in your home. If connecting 9 wires excites your happy place, the term “pigtail” makes you giggle and electrical tape is your friend then… Let’s Get Wired Up!
I hope this help those on the fence… enjoy!