Does 3 Way require the aux?

(Av8rdude) #1

I have several 3/4/5 way switches that I would like to replace. All I care about is have the Master be Z-wave. Do I really need to replace the aux switches? Or can I leave the aux wall switches alone? Does the Z-Wave Aux switch do more than On/Off?

(Chrisb) #2

You do need to replace the AUX switches. Zwave 3-way works different than standard three-way.

Usually in a 3 (or more) setup you have a number of electrical paths between the line (where the power comes from) and the load (light or appliance or whatever). Flipping the switches will open or close one of those multiple electrical paths.

In a typical z-wave setup the master switch is the only one that is connected to that load-switch-line path. The Aux doesn’t touch the main power line at all. Instead the Aux is connected to the main switch via a traveler line that sends a low power pulse to the master indicating when it’s been pushed.

So, if you don’t replace your Aux switches what you’ll end up (depending on how you wire it) is either a completely useless aux switch or, more likely, a situation where you have to have both the Zwave and your old aux turned “on” in order for the light to come on, but either one individually will turn it off.

(Av8rdude) #3

@chrisb Thank you so much for your detailed explanation. I was pretty certain the slave was a proprietary device sending a special signal instead of a traditional switch.
Now to figure out where I can justify installing 3/4 ways in my house.

(Chrisb) #4

One other important thing: Many of the Z-wave switch REQUIRE a neutral. I know my house with it’s old wiring does not have a neutral in in all the switch areas. You might want to check that before investing in a lot of switches.

The only switch I know of that does not require a neutral is the GE/Jasco 45612. Note, however, that even though the switch itself does not require a neutral, the Aux still does. Furthermore, the 45612 is only supposed to be used with incandescent lighting.