I’m properly lost with a 3-way setup for a kitchen light. The light is controlled by one switch by the side door and another switch by the front door. Attached is an existing wiring diagram with dumb toggle switches. Hopefully the diagram is clearer than pictures would have been. I am looking to use the Red series dimmer(s), LZW-31SN, to control this light. The front door gets used way more frequently so I’m looking at one dimmer there at least, but I am okay with whatever would make this work (e.g. two red series dimmer or one red series dimmer with auxiliary, etc.). My questions:
What kind of 3-way setup do I have? (Line/Load in the same box, separate boxes, or in both boxes)?
It looks like I have a neutral in only one box. Is that doable?
How should I wire the LZW-31SN dimmer (or multiples) in this situation?
I marked “line” any wire that showed voltage between it and neutral/ground at all times when tested with a contact voltage tester. I numbered each wire on the diagram to make referencing them easier.
Thanks. Just wanted to confirm what I was seeing. Drawing it out accurately really helps!
This is a neutral Line/Load in the same box, which is the double-gang by the side door. The Inovelli needs to go here. Unfortunately, it can’t go into the front door box. You can use either an Aux or another LZW31-SN if you want to associate the two switches. (If you choose the latter, you must use Z-wave association to connect the two; they can’t be wired together as you would an Aux.)
This is a straightforward 3-way with one variation. Normally, the load would be a 2-wire. But in your case, the load is a 3-wire because a constant hot is also being sent downstream. Not unusual for a leg in the middle of a run.
It works like this. The hot originates at the side door box and is connected to the switch at 14. It is sent switched to the front door box via two travelers, 5 black and 6 red on the 3-wire between the boxes.
At the front door switch, the two travelers, red 2 and black 3 are connected to the non-common screws. The white 1 on that 3-wire carries the switched hot back to the side door box. In the side door box, it’s connected to the red 2 of the 3-wire going to the light.
The white 3 on the 3-wire going to the light sends the neutral. The black 1 on that same 3-wire sends a constant hot downstream for some other use.
I’ll post the Inovelli wiring below. This may be enough to get you going, but if you need more help, post back!
I will use LZW31-SN by the front door as well (through association) only because I have a 10-pack of those at hand already (which is more LZW31-SNs than remaining lights I care about controlling with them).
Let me state the plan for wiring the two Inovellis here to see if I got everything.
In the box by the side door:
Connect the line wire (red 14) to the screw labeled “line” on the Inovelli smart switch.
Connect the neutral screw on the switch to the bundle of white neutrals using a new piece of wire.
Connect the load wire (red 2) to the load screw on the switch. This makes white 4 disconnected but we’ll have a new purpose for this wire down below.
The traveller screw on the switch will be unused.
All the above will leave black 5 and red 6 disconnected but there’s a plan for those down below
In the box by the front door:
(The LZW31-SN will only need a line and a neutral because it will be associated)
Connect the white wire to the neutral screw on the switch. Then in the other box, connect the white 4 to the second neutral screw on the switch to tap into the bundle of neutrals.
Send a hot to this box by—in the other box—connecting black 5 to the second screw slot for “line” on the switch. Then connect the black wire to the “line” screw on the switch in this box.
Cap off the red wire in this box as well as the other end of it in the other box (red 6). Don’t need it.
Load and traveller screws on this switch are unused.
All those steps should get me to this result (attached). Does that look correct?
Just to close the loop here: I completed this 3-way setup via z-wave association at it works great! Thanks so much for your help here @Bry couldn’t have done it without.
(I wish I had enough room in that box with 14 different wires to put a second Inovelli switch for a different light. I’ll give this extension cover plate a try when it arrives. I may need to just live with one dumb switch there - even one Inovelli barely fits as is.)
It depends on the box and the location, but if you can use a plastic box, they make deeper ones. Of course, that means you’ll have to cut the old box out!
