Neutral Wire Q

Hey folks,

Just purchased a ZWave Plus Smart Dimmer Switch and trying to install it. It’s replacing a Lutron Motion Sensing dimmer switch (non-smart). I have an old house, however all the wiring has been updated and all the knob and tube fully shut off/removed.

When I took off the wall plate I saw I have a black wire, white wire, and a ground. I don’t see any additional gang of white wires in the outlet box. The same breaker has additional switches and outlets, but those are independent of this switch (i.e. nothing else controls the lights, and turning off the lights does not impact anything else).

Does this mean I don’t have a neutral wire here and thus cannot install this switch? Please see pix below



The red tape on the wire could be meaningless or it could mean that it is the hot wire. I’m assuming you don’t have a voltage meter or a voltage detector to test with?

If you do have a voltage detector (you can get them at lowes and home depot also) turn the switch off and see which wire is hot. If the white, likely no good. If black, likely good.

You can’t ever really know until you test them…

You want your scenario to be like the image on the left.

Others will say it, so I will. If you need more help you should probably call an electrician.

Most likely his wiring is on your #2 picture. The red tape is Line. One other thing to check is the wiring on the switch beside it. If it’s on the same circuit breaker then you can tap the neutral off of it.
You can try Aeon nano, Fibaro dimmer or lutron dimmer (need lutron bridge).

Thanks for the help! Don’t have a voltage detector, so think I’ll just go the route of returning these and getting one of the very few that don’t need a neutral, or maybe even just getting smart lights instead (9 recessed per room, so it’s not a cheap endeavor, but cheaper than an electrician).

Thanks again

You can get a volt meter on Amazon for less than $10 and it’s going to save you plenty of hair and frustration later cause I am pretty sure you are not going to stop your HA after this switch. Also knowing your circuit will give you more options on devices to buy.

Ok, sure I can pick one up. Are we saying that if the black wire is hot and the white is not, that I can make the switch work with my current situation? If so, what would I connect to the new switch as I only have 2 wires + ground and not 3?

I meant to say there’s a possibility of a neutral wire on the switch beside this one but it’s hard to confirm unless you can figure out your wiring.

Ahh ok. Yeah the switch next to it has it’s electric wire coming into it, also with 2 wires + ground. Same breaker though. I’ll grab one and test out to help gain more info on the setup. Thanks.

Sounded like it has the same wiring Config then. Both with no neutral.

Hope you got your switch up & running.

Here is an easy question for anyone willing…

I have 3 switches in same box, could I convert all of them to smart switches using that 1 bundle of white wires?(see pic) Meaning, do I run a pigtail from each smart switch to that bundle? It’ll be a lot of wires going into the wire nut?

I did that, but I split the bundle to no more than 5 wires in the nut and jumpers between them. You can also jumper switch to switch, as they accommodate 2 wires on each terminal and then just run from last one to wirenut.

I’m new to this & still learning wiring terminology… any pics that could describe what you mean by ‘jumper switch to switch’?

Are you saying run a white wire from bundle to switch 1, then another white wire from switch 1 to switch 2, then to switch 3, then finally from 3 back to bundle?
Or just white wires between all 3, & last one to bundle?

That’s all you need.

Not needed

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