Replacing a single pole dimmer switch with a 3-way one

[austin99]

Hi there,
I currently have a dual dimmer switch which is wired as two separate single pole switches. For each light circuit I have just two wires into two separate dimmer modules.
I want to replace this with another dual dimmer switch which supports home automation (z-wave) and unfortunately the only module that was available that was a dual dimmer switch was a 3-way one. And ideally I'd like to avoid having to rewire both circuits -I know this may well fall into the category of having ones cake and eating it!

The new switch has the following connectors (as per the manual)
* L: Line Voltage Input
* N: Line Neutral
* N: Load Neutral (Line Neutral)
* 1: Switched Load Output
* 2: Auxiliary Switch reference (Line Neutral)
* 3: Auxiliary Switch Signal Input

So I thought I'd just try and get the switch to control just one of the lighting circuits initially. The unit obviously needs power on the L and N terminals (I've temporarily used one of the light circuits for this) and this works fine (the blue LED comes on and the device is detectable on the home automation network). But I'm not sure how to connect the 2 wires from the remaining lighting circuit that I want to control to the remaining terminals. Can someone help me out - I'm aware that if I'm out of my depth I'll go down the route of getting a qualified electrician in, but I'd like to understand the problem first.

Any help is appreciated.

 

[ban-all-sheds]

You don't have to use it as a 3-way, surely?

And it's only single switch, so won't control 2 lights independently except via the Z-wave morse code stuff.

Basically you need L&N in and L&N out. Neither of your cables will have a neutral and neither of the lights the existing switch controls will be expecting L&N on their switch cable.

So you can change where the supply cable is connected, which will stop one light working, and recable how the other one connects to its light.

I have to say though that if you're struggling with the basics of circuits, trying to leap straight into automation is definitely a run before you can walk kind of idea.

 

[austin99]

Thanks for the reply

You don't have to use it as a 3-way, surely?

I guess not.

And it's only single switch, so won't control 2 lights independently

I posted the link to the wrong manual - I meant to link to this one

Basically you need L&N in and L&N out. Neither of your cables will have a neutral and neither of the lights the existing switch controls will be expecting L&N on their switch cable.

So you can change where the supply cable is connected, which will stop one light working, and recable how the other one connects to its light.

Ok - can you elaborate a bit more.

I have to say though that if you're struggling with the basics of circuits, trying to leap straight into automation is definitely a run before you can walk kind of idea.

All of the other z-wave devices are in and working - all the other switches and dimmers were 2-wire so they were simple swaps. It's just this last remaining 3-way one that has got me scratching my head. But point taken, I'll only proceed to wire it up if I fully understand it.

 

[ban-all-sheds]

That 2-button switch is wired just the same (note that they are both called "3-way dimmers"). The only difference between that and the 1-button one you showed first is that Groups 2 & 3 are controlled by tapping the RH button once or twice rather than the single button 2 or 3 times.

(Anyone who ends up buying your house is going to love you.... )

So you have to take a permanent L&N to it, and from it goes a switched live & neutral to a light (one of the ones that was on the old switch), or group of lights.

The other light that was on the old switch will have to be connected to another Z-wave device which you associate into Group 2 or Group 3 so that you can control it from the RH button. At least, that's what I understand from a quick read-through of those info sheets.

It's not a direct replacement for a regular 2-gang switch.