Unexpected Power Outlet Wiring


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Old 12-15-15, 08:29 AM
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Unexpected Power Outlet Wiring

Hello everyone,
First time poster here. I'm installing a new power outlet and HDMI input behind our TV, for my wife's Christmas present. I've run the 14/2 wire, and I'm ready to begin wiring it to a power outlet below the TV, but I'm not sure exactly how to wire it up correctly.

When my wife was out of the house, I removed the outlet and inspected the electrical box. There are currently three inlets to the box, and I've punch out a fourth inlet, which will lead to my new outlet. The box currently has the following configuration:

Inlet 1:
Hot wire goes to right side
Neutral wire goes to left side

Inlet 2:
Hot wire goes to Inlet 3
Neutral wire goes to left side

Inlet 3:
Hot wire goes to Inlet 2 (described above)
Another hot wire goes to right side
Ground goes to right side (I think the ground post is on the right side; I need to double-check this)

I believe Inlet 1 leads to a power outlet, Inlet 2 leads to another power outlet, and Inlet 3 leads to a switch and intercom box.

Does this configuration make any sense? I don't understand why Inlet 2 would have a hot wire going to Inlet 3 and why the only ground wire comes from Inlet 3. Whatever is going on, the outlet functions as expected; we've been powering our TV and PC from this outlet for 2 years now.

Can anyone help me sort out this mystery? Also, with this in mind, how might I wire up the new line to this configuration?

Thanks for your help!
 
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Old 12-15-15, 11:32 AM
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My first thought is that the box may be full and adding a fourth cable may overfill it. You may need to replace the box with a larger one.

I'm not entirely understanding your description, but it sounds like you may have a switch loop. Is half of the described receptacle turned on by the switch?

Can you draw a diagram or take a clear picture of the wiring?
 
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Old 12-15-15, 12:31 PM
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Yes! There is a switch to control power to the outlet! Although, I think it controls the whole receptacle; we leave it on all the time since it powers our TV, computer and internet/cable, and I'm at work right now, so I can't verify that.

Here is a diagram I drew of the electrical box:
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Is that helpful?
 
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Old 12-15-15, 03:37 PM
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Ok, I've got the power off and the receptacle out of the wall for a second look. I can confirm half of the outlet is wired to a switch, and the other half is always hot. I've studied up on switch wiring, and now I understand what's going on, except for the ground. It's not connected to the green post, it's connected to one of the non-jumpered hot posts. What is the purpose of this?
 
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Old 12-15-15, 03:48 PM
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except for the ground. It's not connected to the green post, it's connected to one of the non-jumpered hot posts. What is the purpose of this?
No idea.... but it is not correct. The ground wire should ONLY ever be on the green ground screw.

If your diagram is correct.... someone is using the ground wire as a switched hot wire.
You will need to look at the switch and see if that is what has been done.

In looking at your drawing... it is not correct. At wire 3 you are showing two hot wires and no neutral.
 
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Old 12-15-15, 04:00 PM
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So I pulled out the switch, and lo and behold, the two "hot" wires are connected to the top of the switch, and the "ground" is connected to the bottom. Nothing is connected to the ground. So you're right, the "ground" is just a switched hot wire.
 
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Old 12-15-15, 04:03 PM
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Then that is an extreme hazard that needs to be corrected ASAP.
 
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Old 12-15-15, 04:08 PM
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lo and behold, the two "hot" wires are connected to the top of the switch
Do you mean one black and one white to the same screw? Are there any other wires in the box?
"ground" is connected to the bottom.
You have a real mess there that needs to be sorted out and fixed before you go further. If the room has a switched ceiling light you may be able to just abandon that switch.

Can you take some pictures of the actual wiring at both boxes and post them?
 
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Old 12-15-15, 04:16 PM
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Awesome (not!)

So, I need to reconnect the grounds to their respective green posts. Move one of the hot wires on the switch to the other post (can I just disconnect the switch entirely? I don't like having it). Then, I need to find a grounding source and connect it to the outlet so the system is grounded.

Is that right?

I have no idea what to ground it to, if what I thought was a grounding wire isn't actually grounded.
 
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Old 12-15-15, 04:24 PM
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I don't know if I can post pictures from my phone. I can't use my computer because the power is off.

Edit: got it!
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You can't tell, but the cream colored wires attach to a jumped screw, in the back.


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This is the switch. Both brown wires connect to the same screw. The yellow goes to the other one.
 
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Old 12-15-15, 04:32 PM
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Setting your discovered problem aside for a few minutes, you ran a new 14-2 cable so why do you need it to go into an existing box. Why not just cut a new - old work box in for a new duplex receptacle?
 
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Old 12-15-15, 04:41 PM
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I'm not sure what you mean. I have another hole partially cut, which I am going to insert my new power/hdmi receptacle. But I still need to draw power from somewhere.
 
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Old 12-15-15, 04:53 PM
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Wait a minute.... yellow is not ground. Yellow CAN be a switched hot wire.

Your wiring is in conduit ?? If yes.... no ground wire will be present.

The wiring on the switch and receptacle.... although a little messy.... is correct.
 
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Old 12-15-15, 05:01 PM
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Yes, it is in metal conduit. I see that now, that yellow (at least in my case) is not ground. So is the metal conduit grounded at circuit box, or something? Do I not need to worry about grounding my outlets?
 
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Old 12-15-15, 05:02 PM
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At the receptacle..... remove the white wires. Cut that loop so that you have two white wires. Add a short piece of the same size wire and connect it to the receptacle where the two whites were. To these three white wires....add the white from your new receptacle. Wire nut it off. You'll have four white wires in the wirenut.

Remove the brown wire from the receptacle. Add a short piece of wire to it and connect it to the receptacle. To this connection.... add your black wire to your new receptacle. Wire nut it off. You'll have two black wires and a brown in the wirenut.

You will need to connect your bare ground wire to a screw inside the metal box. A green ground screw would be ideal if you have a place for it. You could wrap the ground wire around the screw and then use the tail to connect to the receptacle.
 
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Old 12-15-15, 05:11 PM
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But I still need to draw power from somewhere.
By running the new 14-2 cable I thought you meant you had run a new circuit which isn't a bad idea.
 
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Old 12-15-15, 05:39 PM
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I just realized that in the picture of the receptacle, there is a brown wire that is hiding right behind the yellow one, but it connects to the bottom screw, so that both brown wires are connected to the same screw. Does that change anything?

I think I understand what you're suggesting. Nut all of the cream wires together, to create one large neutral...bundle. Then, remove the two brown wires and nut them together with a new piece of wire on the bottom screw. This will create one switched outlet (yellow) and one hot outlet plus the new outlet will also be hot. Correct?

Plus, I have to connect the new ground to the green screw, of course.
 
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Old 12-15-15, 05:55 PM
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Yes..... you have it correct. It's much neater and more effective to have just one wire to each terminal.
 
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Old 12-16-15, 06:35 AM
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I see you are in IL. Some parts around the Chicagoland area do not allow NM cable and require conduit.
 
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Old 12-16-15, 11:37 AM
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I see you are in IL. Some parts around the Chicagoland area do not allow NM cable and require conduit.
Considering there are yellow and brown wires in the mix you can be pretty certain the OP has a conduit system.
 
 

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