What is going on with these light switches

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Old 01-03-19, 08:57 AM
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What is going on with these light switches

Member is in Argentina.

I'm a little confused. The top switch appears to control nothing and I wanted to hook it up to something new.

The bottom switch controls some outside light.

The part that confuses me is that when the outside light is on, there is no power at any of the terminals. When the outside light is off, there is power at terminal 3 only.

Flipping the top switch does not affect this at all.

 

Last edited by ray2047; 01-03-19 at 09:15 AM.
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Old 01-03-19, 09:17 AM
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Sounds like you used a non contact tester. If so ypor results are meaningless. However it seems power is at the light so you don't have both sides of the circuit there.
 
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Old 01-03-19, 09:41 AM
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Ok I've done a little more digging and this is what appears to be be what is going on.

Following the wires, I found a photocell with along enough lead to put it outside, tucked into the ceiling and wired into this whole mess.

Does this make sense to you guys? Can you put a photocell on the negative?

 
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Old 01-03-19, 09:45 AM
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Ray,

I used one of those little screw drivers that has a neon light inside. I'm not sure if that's what you mean by non-contact tester.
 
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Old 01-03-19, 10:43 AM
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So the switch box has hot neutral and ground as well as the three wires, two switches on un switched that run to the light. The hot and neutral are the same color.

it seems to me that the most likely thing was that since polarity didnít matter for the lights or the two wire photocell that they just didnít bother to check which was which. They whole diagram would look a lot more normal to me if instead of neutral being switched, it was the line. Anyways since the light Iím adding to the other switch is a LED strip, I do care about the polarity so Iím just going to swap the center wire from neutral to line and the unswitched wire to neutral and leave the photocell wiring alone
 
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Old 01-03-19, 03:18 PM
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I used one of those little screw drivers that has a neon light inside.
https://www.youtube.com/watch?v=wLAJ-keFmpk

Is this what you used?
That is not a non-contact tester, but the result you get is basically the same.
Not as safe as non-contact tester and also could give you wrong result if you body is well insulated from ground. (Which is what is discussed in the video as well).

Did you find which is live and which is neutral using this tester?
Switch on neutral side is unsafe and wrong no matter which country you are in.
Some countries with non-polarized system use 2 pole switches for this reason.

If you are 100% positive you have neutral and live reversed, switch it, but check other wiring as well. It could get reverse polarity in other circuit if you reverse it in the wrong place.
 
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