Which neutral to use

smc

Senior Member
Joined
Sep 19, 2005
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518
@Geoff.D may want to comment. I'm not comfortable making a suggestion without knowing why that single neutral wire is where it is.
 

smc

Senior Member
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Sep 19, 2005
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518
Additional question - everything works the way it is now? the lights go on and off, and there aren't any other switches in the house that aren't working correctly?
 

Steamy Tom

Executive Member
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Jan 23, 2019
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****. The top light is part of another light in the lounge. So a two-way thing
it isn't the end of the world, i would personally alter the wiring to make it a one way switch and then make the other switch point use a scene to toggle this one.
 

Geoff.D

Honorary Master
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Aug 4, 2005
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14,328
Yes that is a two-way switch arrangement for at least one of the light fittings with another switch somewhere else also controlling the power to the light fitting, where the available cables have been used, breaking the normal colour code rules because of what is available. Another example of pathetic registered electricians at work, too damn lazy to ensure the correct cables with the correct colour codes was used in the original construction.

I will have to think about how you can use the SONOFF arrangement with a two-way switch setup before suggesting how the wiring should be. In the meantime, that lone black wire will have to proven to NOT be a neutral wire before you do anything. And you will have to determine which two-way switch is the "master" ie. the one where incoming supply is connected.

I have a diagram somewhere of what a two-way switch arrangement can look like. Unfortunately, there are a few variations also and I am pretty sure at least one of those variations will not work too well with a SONOFF switch added.
 

The_Ogre

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Apr 30, 2010
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21,868
Yes that is a two-way switch arrangement for at least one of the light fittings with another switch somewhere else also controlling the power to the light fitting, where the available cables have been used, breaking the normal colour code rules because of what is available. Another example of pathetic registered electricians at work, too damn lazy to ensure the correct cables with the correct colour codes was used in the original construction.

I will have to think about how you can use the SONOFF arrangement with a two-way switch setup before suggesting how the wiring should be. In the meantime, that lone black wire will have to proven to NOT be a neutral wire before you do anything. And you will have to determine which two-way switch is the "master" ie. the one where incoming supply is connected.

I have a diagram somewhere of what a two-way switch arrangement can look like. Unfortunately, there are a few variations also and I am pretty sure at least one of those variations will not work too well with a SONOFF switch added.
OK, cool. I'm going to close it up and wait for your advice.

The lounge downlighters can be controlled either by that top switch or by another one in the passage. The one in the passage is part of a switch with three other buttons - so the switch has a total of four buttons.

One of those four buttons is also part of a two way configuration where the other switch is at the bottom end of the passage.

There are 9 down lighters in my lounge. Three of those are controlled by the button/switch in question. My TV is wall mounted and those three lights is directly above it. So as you can imagine, we hardly ever use those lights. Only when we need to enter or exit the house through the front door - which hardly ever happens since we enter and exit through the garage.

So I don't mind losing that particular button. If I can only control those three down lights with the button which is part of the four button switch in the passage, it won't be an issue at all. The same goes for the two buttons on either end of my passage that operate the passage lights.

I'm now beginning to think that maybe I need to get an electrician in, but I don't want to pay if I don't have to :ROFL:
 

smc

Senior Member
Joined
Sep 19, 2005
Messages
518
If that "stray neutral" is indeed the wiring for an old-style two-wire double switch arrangement where whoever installed it didn't bother to use another color code, then I don't think you will be able to duplicate the exact behavior of the two existing switches. Usually they're wired such that if the light is on, you can switch it off at ether switch, and if its off, you can also switch it on at either switch. So far as I am aware, you could wire two Sonoffs such that you could switch on at either switch, but they would both have to be off for the light to be off.

If you decide to change to having only having one switch per bank of lights, then you'd have to identify which the red is that is paired with that black, and disconnect both the red and black at both ends, and disable. Then wiring the Sonoff would be basically the same as the previous switch.
 

Steamy Tom

Executive Member
Joined
Jan 23, 2019
Messages
5,468
If that "stray neutral" is indeed the wiring for an old-style two-wire double switch arrangement where whoever installed it didn't bother to use another color code, then I don't think you will be able to duplicate the exact behavior of the two existing switches. Usually they're wired such that if the light is on, you can switch it off at ether switch, and if its off, you can also switch it on at either switch. So far as I am aware, you could wire two Sonoffs such that you could switch on at either switch, but they would both have to be off for the light to be off.

If you decide to change to having only having one switch per bank of lights, then you'd have to identify which the red is that is paired with that black, and disconnect both the red and black at both ends, and disable. Then wiring the Sonoff would be basically the same as the previous switch.
i would go with disconnecting the wires so that only the one is connected to the light, make it the master and then just wire the other switch up to have power and make a scene.
 
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