2 Power Sources, 1 Switch

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image969
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2 Power Sources, 1 Switch

Post by image969 » Fri Aug 26, 2016 10:00 am

I have 1 breaker going to a light switch the controls an outside light. it works fine.

I have a second light outside controled by a second switch that is powered by a second breaker. This is a double hot switch(both black and white are hot at the switch to make sure Im explaining it right)

I'd like to remove this switch and run the black and white hot wires up through the attic, across the house and down to the first switch that controls the first outside light.

Is this ok to do? Can I have what seems to be 2 seperate power sources on the same light switch? It's literally 2 lights outside only. so I know there would not be an overload. Thanks.

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Aaron
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Re: 2 Power Sources, 1 Switch

Post by Aaron » Fri Aug 26, 2016 5:49 pm

You want to control both lights with just the first switch you mentioned?

From what you describe, your second switch has what's called a switch loop. So the power comes into the switch on one wire, and when the switch is turned in, power leaves the switch on the second wire. You didn't mention how the first switch was wired, but I assume it's the other method: where power enters the box, the neutral (white) passes through the box, and the hot (black) is open or closed with the switch.

If you want the first switch to control both lights, you need to not only wire from the first switch's location to the second light, but you will also need to remove the wiring from the power source to that second light and from the second light to the switch.

Then you just wire it the same way as the first light, only instead of the hot wire leaving the switch to go to first light, you would make a pigtail and tap the two lights off that pigtail from the switch.

Hope this makes sense!

image969
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Re: 2 Power Sources, 1 Switch

Post by image969 » Fri Aug 26, 2016 7:55 pm

It does make sense. However if I can't locate where the power source is coming from on the second switch. What happens if I take the black and the white on the second switch and just run it to the black and the black on the first switch?

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Shannon
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Re: 2 Power Sources, 1 Switch

Post by Shannon » Sat Aug 27, 2016 7:29 am

image969 wrote:It does make sense. However if I can't locate where the power source is coming from on the second switch. What happens if I take the black and the white on the second switch and just run it to the black and the black on the first switch?
Simple. BOOM!
You will have 240 volts going through that one switch frying the lights and switch!
Finding and disconnecting that power source at the second light should be simple, remove the second light fixture and the power source will be in that j box. Disconnect , cap the wires with wire nuts and either remove the wire that went fr the light to switch and install a new one from light all the way to switch or continue a wire from the switch location to the next switch or light location you wanted to use.
Sorry Aaron , I did not mean to butt in here. :D
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Aaron
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Re: 2 Power Sources, 1 Switch

Post by Aaron » Sat Aug 27, 2016 2:47 pm

You will need to install two regular single-pole switches at the first location to switch the two lights. Replace the single-gang box with a dual-gang box. Might have to cut into your drywall to do this, but you'll be making a mess fishing wire to it anyway.

If you don't want a dual-gang box or can't fit one on the wall in a narrow space, there are duplex switches that fit in a single-gang space. You use a duplex receptacle cover with them. I'm not a big fan of these switches because they're sideways and aesthetically look a little strange. But they are a good solution when nothing better can be done.

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Shannon
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Re: 2 Power Sources, 1 Switch

Post by Shannon » Sun Aug 28, 2016 10:18 am

Aaron wrote:...If you don't want a dual-gang box or can't fit one on the wall in a narrow space, there are duplex switches that fit in a single-gang space...
Good idea I never thought of a second switch , I was thinking they wanted to control both lights with the one switch.
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Aaron
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Re: 2 Power Sources, 1 Switch

Post by Aaron » Sun Aug 28, 2016 1:09 pm

Shannon wrote:Good idea I never thought of a second switch , I was thinking they wanted to control both lights with the one switch.
Yeah, the second switch would be easier and won't involve any concern with how each light is powered or wired. You're really just moving the existing switch to a new location and wiring it the same way.

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