# light switch with 2 hot wires



## srmusaf (Dec 6, 2010)

I was replacing a light switch and found it has two hot wires. Actually it looked like this. 3 black wires, one single and two together and pig tailed into one. I seperated all of the wires and found the 2 wires that were pigtailed, one was hot one was not. The single wire was hot. What the  is that about???


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## MikeVila (Nov 2, 2008)

It's a hot feed that is powering something down line also. Possible outlet is picking up its power feed from here.


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## srmusaf (Dec 6, 2010)

*2 hot wires to light switch*

But if a wire that is hot is connected to a wire that is not and pigtailed to one screw on the switch and another hot wire is connected to the other screw, what is the point of having the switch?


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## a7ecorsair (Jun 1, 2010)

So what you are saying it the light switch didn't work before you took things apart...
What is this switch expected to control?


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## MikeVila (Nov 2, 2008)

On your light switch you have 2 black wires pigtailed together and connected to the bottom screw? Using a tester 1 is constant hot and the other is not which is the feeder down line. You have another black wire connected to the top screw of the switch. You tested it and it is a constant hot?


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## joed (Mar 13, 2005)

srmusaf said:


> But if a wire that is hot is connected to a wire that is not and pigtailed to one screw on the switch and another hot wire is connected to the other screw, what is the point of having the switch?


The point is you have power coming in and two powers going out. One power is always on and the other power is controlled by the switch.


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## srmusaf (Dec 6, 2010)

*Light switch*

There are 3 black wires in the switch box that is supposed to control a light fixture. *With the switch removed*, wire # 1 is constant hot. Wire # 2 is constant hot. Wire # 3 is not hot. Wire # 1 is connected to one of the screws on the switch. Wires # 2 & 3 were wirenutted together with a short piece of wire as a pigtail and the pigtail was connected to the other screw on the switch. I gues I'm confused because this does not seem normal. :cursing:


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## oberkc (Dec 3, 2009)

I'm confused. This does not seem normal to me, either. 

I wonder if it is one of those "phantom" power cases, where some voltage testers can show a voltage that would go away if a load is a load is applied. How did you determine that there is a voltage? Non-contact probe?

Are the two conductors (wires 1 and 2) showing a voltage in the same sheath? Is it possible that this is a switch leg from the light fixture, with the load (wire 1) picking up an induced voltage and the actual supply (wire number 2) providing power to downstream devices (wire number 3) as well as the switch?


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## srmusaf (Dec 6, 2010)

*Light switch*

I removed the switch and used a multi meter with contact probes. The black probe, I touched to the Ground. The red probe I contacted to each black wire. The black wire that is not hot, I assumed would be powered to the fixture when the switch was flipped but I can't understand why it would be tied to a wire that is constant hot.


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## oberkc (Dec 3, 2009)

What about my question regarding wire grouping. Are wires 1 and 2 in the same sheath? 

Based on the posts of some of the pro electricians, I understand that this "phantom" voltage can be seen even by some digital probe-type voltage testers. 

How much trouble is it to remove the light fixture and inspect the wiring?


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## srmusaf (Dec 6, 2010)

All three are in different sheaths. I removed the fixture and my next step is to ohm the wire that I assume is the supply to the light, the non hot wire


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## oberkc (Dec 3, 2009)

Different sheaths! There goes my theory!

Other than further investigation to identify where wires come and go (as you are planning), I am out of ideas. Hopefully, this will provide a clue as to your voltage on your load.


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## jbfan (Jul 1, 2004)

If it worked before, why did you undo anything?


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## srmusaf (Dec 6, 2010)

jbfan said:


> If it worked before, why did you undo anything?


Thats why I was checking it out, it wasn't working.


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## joed (Mar 13, 2005)

What wasn't working? What doesn't work if you leave all the blacks apart and power up the circuit? What does work if connect all the blacks together and all the whites together?


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## srmusaf (Dec 6, 2010)

*Light switch*

C'mon joed, what a dumb thing to say. The wires were connected to the switch, the light was not working, I took the switch apart to find out why. :detective:


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## psuryan (Oct 26, 2010)

The light was not working, or the switch was not controlling the light?

Try going without the switch for a try, see if both hots are really hot, try one and then the other.

The only thing I can think of is that someone tried to make it a 3 way. Is there a second switch for the light? I can see someone putting hots to two switches, then joining them on the light side of the switches. This way, either switch flipped on would turn the light on, you would just not have the ability to turn it off from the other end. 

Thats the only thing I can think of that would make someone do that.

In the light itself, do you only have one cable coming in, or is there a second cable from that box?


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## a7ecorsair (Jun 1, 2010)

srmusaf said:


> C'mon joed, what a dumb thing to say. The wires were connected to the switch, the light was not working, I took the switch apart to find out why. :detective:


You are obviously not a troubleshooter and you don't understand one of the most basic circuits it residential wiring. In your original posting all you said was you were changing a switch. To us, that could mean you didn't like the color or the switch was physically broken. It wasn't until post 14 that you said it didn't work......
So, you are troubleshooting some problem that has not worked for some time and maybe never worked for you. Switch circuits come in two basic flavors: 1) Power is in the light fixture and there is a switch leg that controls it. That means there is a hot and neutral at the light. 2) Power is in the switch box and there is a neutral and a switched hot going to the light.
You need to tell us, since we cannot see your setup, how your fixture is wired. What is at the fixture for wiring?


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## joed (Mar 13, 2005)

joed said:


> What wasn't working? What doesn't work if you leave all the blacks apart and power up the circuit? What does work if connect all the blacks together and all the whites together?


Please try these two tests and post back with the results. Can we assume you already changed the light bulb?


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## acftmech (Dec 7, 2010)

Are you sure this isn't someones attempt to wire a two switch circuit? Wire 1 would be the hot (line) in, wire 2 would be a hot in from a second switch (thus bypassing the switch) and wire 3 would be the the load out to your light. In any case if your light isn't working it seams you have an open between the switch and the light.


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## oberkc (Dec 3, 2009)

> Please try these two tests and post back with the results. Can we assume you already changed the light bulb?


JoeD, 

If, by chance, this circuit is really screwed up and if there are truly two hots, and if they are on separate legs, would it be a hazard to try to connect them together. 

Yes, I agree. This is unlikely.


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## joed (Mar 13, 2005)

I give up. Call an electrician is my best advice to you now.


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## jerrvez (5 mo ago)

it is my dads old house 90 years old i took it apart three cables 2 hot one not works 2 lights some tims got shock and thats where i at i have wired 2 homes 4garages i no pro so thats why i posted whhst1


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## afjes2015 (May 21, 2015)

A little punctuation would help us understand what you are saying. Difficult to understand one run-on 
sentence.

Oups! Just realized this is a 12 year old thread


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