No neutral wire in add-on switch box

(Douglas L) #1

Hi, everyone. I came across a switch in my daughters bedroom that has a neutral line in the main box but nothing in the add- on box (it’s a three-way switch). Has anyone found a way to connect an add-on switch without a neutral line? I don’t want to try to repurpose the grounding wire as the neutral. Many thanks.

(Jason) #2

I think you might be able to use two aeon micro switches that install behind the switch, but am not positive.

(Jason) #3

I’m questioning whether you could now, I don’t know enough about wiring maybe. But here are the instructions.


Definitely don’t repurpose the ground wire.

Unfortunately the Aeotec micros also require a neutral, so they won’t help you unless there is someplace else on the circuit you can move them where there is a neutral.

Using a “Virtual Auxiliary”

There are some options depending on exactly what you’re trying to do. Sometimes you can replace an auxiliary switch with a battery operated switch like the Cooper RF9500. Or even the smartenIt 3 toggle.

Since the auxiliary normally doesn’t have to actually control the load to the light, you can take it off of the circuit altogether, just like you would with a handheld remote. Then the auxiliary sends a message to the hub, and the hub sends a message to the master switch. This is called a “virtual auxiliary” or a “virtual three-way.”

The Figure 8 Problem

Depending on exactly how the existing auxiliary is wired, though, you may have to do some rewiring to make sure you have both a hot and a load wire at the master switch before you can remove the aux from the circuit. In some set ups you get kind of a figure 8 situation where The existing aux is necessary to the circuit or the light won’t come on. It’s usually not complicated once you figure out exactly what’s going on, but you may need an electrician to get everything set up correctly.

Essentially, if you have a single pole switch with no auxiliary, it’s easy to replace that with a networked master as long as there’s a neutral there. Then you can add as many “virtual auxiliaries” as you like, including the battery operated ones that I mentioned.

However, once there is a nonnetworked master connected with traveler wires to a nonnetworked auxiliary, it’s not always possible to just swap things in and out or to try to ignore the auxiliary. It just depends on the exact wiring that was used. So sometimes you need to take a step back and figure out how the single pole master will work independent of the auxiliaries. And then add the virtual auxiliaries back in.

The other alternative is usually to “fish up” a neutral from somewhere else in the wall. This is discussed in the lighting FAQ.

The Lighting FAQ

Anyway, the lighting FAQ discusses various options, so it should help:

(Ray) #5

A GE add on switch needs only a traveler, neutral and a ground. You have at least 3 wires and a ground at each box. No white wire doesn’t mean there is no neutral. I would try to figure out which 3 ways wiring configuration first. Here’s a link to 8 different 3 ways.

(Ray) #6

Nice to see you back to the mad house @JDRoberts!

(The Viking AKA "Holy Crap You're a Giant!") #7

@Navat604 has it right.
You have a three way switch in the remote location, you can repurpose one of those wires as a neutral, one as a traveler.

You may need to pull the light fixture and move a wire so that you have neutral in the remote box. I’ve had to do this a couple of times.

(Rfg81) #8

Could you give me an explanation on how to do this? I have options #3 in

(Michael) #9

Basing left and right from the diagram, the left switch should remain the same. In your light fixture keep the red wires connected but connect the black coming from the left switch to the black wire on the fixture. Then connect the white wire from the right switch to the other 2 white wires going to the fixture and left switch. The black wire from the right switch is no longer needed, so just put a cap on it in the fixture and right box. Then connect the red and white wires to your Aux on the right switch.

(Rfg81) #10

Thanks for your quick answer! I will try to do it as soon as I get home.

(The Viking AKA "Holy Crap You're a Giant!") #11

This is the correct answer @ritchierich. :smile:

Black from left switch to black on light. Disconnect black to right switch, cap on both ends with wirenut.

White is neutral, so tie the two whites in the light box together, and add a pigtail to the light fixture from the white wire for the neutral.

Red becomes your auxiliary traveler wire.

(Michael) #12

Believe we are saying the same thing.

(Ray) #13

It’s the reason why I usually say. The black wire on the “light bulb” :smile: but yeah you both got it right.

(The Viking AKA "Holy Crap You're a Giant!") #14

Sorry @ritchierich.
I wasn’t trying to step on your toes. When I said “This is the correct answer”, it was confirming that yes, your answer was indeed the correct one.

I write documentation as part of my day job to allow non-technical users to easily use a highly technical device/process.

Your description was accurate, but I sort of auto-responded to the post with what I deemed to be a slightly easier to read guide.

I have to remember to refrain from doing that. lol

(Rfg81) #15

Thanks for you both, I will try it tonight and report back :slight_smile:

(Rfg81) #16

It worked, thank you so much!

(Brad) #17

I have a nearly identical situation. Instead of having option #3, as @rfg81 had here, I believe I have option 4. I’m coming up with my own solution, but I’d like to check my work against someone with more experience.

So, if I have wiring as shown in Diagram #4, what would I rewire to ensure that I have line, load, traveler, and neutral at the master switch; and load, traveler, and neutral at the auxiliary switch?

CC & TIA: @navat604, @synthesis

(The Viking AKA "Holy Crap You're a Giant!") #18

This one is easy enough.
If your wiring junctions are primarily in the light box(es), you have two potential options.
All of the three way wire junctions are in one box, and the power to the second light branches from the first one, or you have it identical to the drawing in which all wiring passes through both light boxes.

The first one is simple. You connect the red from Source switch to red at Secondary switch by tying them together in the junction box. As long as red is tied to itself through all of the boxes from one switch to the other, and no other wires are tied into this one, then you now have a single continuous traveler wire to link the traveler on the slave switch to the traveler input on the master.

Black from the source goes into the line connector on the master.
Load goes from the master to the lights. (black to black to black). Cap the black in the slave switch box and/or in the light box. You won’t need it unless the load actually passes through the switch box.
White is neutral in all cases. Tie all neutrals together.

You now have the ground, neutral and red traveler wire in the slave box. That’s all you need.
The slave switch doesn’t pass any actual power.

Edit: Think of it this way. Your source switch box is where power comes in. In a single two-way switch setup (one switch, one or more lights controlled by that one switch), you are controlling power at that box and nowhere else.
Add a three way switch and you are flipping the power back and forth between the two switches depending on where you are and what you toggle.

In the GE Z-Wave switches, your slave switch isn’t doing anything more than turning on/off the master switch in the source box using that traveler wire. It’s just issuing the command to turn on or off from the remote location. So you don’t need power at the slave switch. You simple need the white neutral from the source box to travel through the light boxes (tying neutral in at each light) and into the slave box (providing neutral for the slave switch.)
Then you need the red traveler wire to go from the traveler terminal on the master switch to the traveler terminal on the slave switch, with nothing else in between those two points.
Add a ground, all done. Apply power and away you go.

(Brad) #19

Thanks much. It has schematically come together for me. My personal journey to this place found the schematics for what I’m supposed to have with my z-wave switches very easy to envision, but coming to understand what I currently have in my walls was the hard part.

All of my home’s many 3-way switches are wired this way, with one of the boxes not having the neutral bundle that is assumed there by the in-box diagrams and the YouTube installation videos. I’d strongly hoped there was a solution, and this appears to be it.

Thanks again!

(Michael) #20

I am struggling with the wiring of my switches as well. From the link provided earlier in the thread, my current switch setup follows Option #9. My line and load are in one junction box with the second box just having a switch.

“If” I am reading this thread correctly, I need to wire the main switch just like a standard 2-way switch and light. Then the feeder that goes to the other box just needs to be tied to the traveler and neutral? I don’t need line at all in the 2nd box?