Wiring electrical outlet with four wires

Old 11-16-07, 10:58 AM
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Wiring electrical outlet with four wires

I am replacing the beige electrical outlets in my house with white ones. The outlets I've worked on so far have four wires -2 white and 2 black (and a ground wire) connected to the back of the electrical outlet. I know that the black wires are attached on the side with the brass screws or the small slit and the white wires are connected to the side with the silver screws or wide slit. I initially didn't take note of each wires location. My question is does it matter where each wire goes as long as it's on the correct side of the electrical outlet? Meaning, if one of the black wires was connected to the bottom screw on the hot side and when I rewired it I placed that black wire on the top screw of the hot side would that make any difference? I hope I explained it well enough for an answer. Thanks.
Old 11-16-07, 11:10 AM
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Personally, I would have the the wires coming in (black and white) on the top set of screws and the wires going out (black and white) on the bottom set of screws. Or ever splice a pigtail, so only one black wire and one white wire will be on the device.
Old 11-16-07, 11:48 AM
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No, it does not matter unless the receptacle is GFCI or either of the brass tabs on the existing receptacle are removed. Any receptacle for which the top or bottom is controlled by a switch will have one or more broken tabs.

If the receptacle is GFCI, then you need to properly identify the LINE and LOAD wires and put those in the right spots. If either of the tabs are broken, then you need to break the corresponding tabs on the new receptacle and connect the wires in the same positions as on the old receptacle.

Intact tab:

Broken tab:

Last edited by ibpooks; 11-16-07 at 11:54 AM. Reason: Better images.
Old 11-16-07, 11:56 AM
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You need to pay attention to the wiring BEFORE you disconnect anything.

It is NOT always true that the wires are white to the silver side and black to the brass side. A switch loop could exist, where a white wire is connected to the brass side.

A receptacle could be half switched, half not. If you mix the wires up it will not behave the same way.

A red wire could be involved.

Bottom line: Thoroughly examine the wiring and the receptacle before you disconnect anything. Make notes or take a digital picture if you have to. Sometimes people make a mistake, and it takes them hours and perhaps costs them dollars to fix it, all because they didn;t make note of the original wiring.
Old 11-16-07, 12:28 PM
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I don't believe there are any conditions on a 120-volt circuit in which it would be correct to attach a white wire to a brass screw, even with a switch loop.

Note that sometimes there are wires in the box that don't attach to the receptacle at all. So the black-to-brass and white-to-silver is far from a universal rule. There's no substitute for research and for paying attention.

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