I just want to plug things in

January 3, 2008 10:12 AM

I have a light switch on the wall that controls both an overhead light and an outleft. I'd like it to only control the overhead light, while still sending power on to the outlet.

Inside the switch box, I have two sets of wires - one that is red-white-black-ground and one white-black-ground. Both black wires go to the switch - one to a screw, one to a hole connector. The white wire from the 3 wire set goes to the other hole connector. The red wire and the white wire from the 2 wire set are capped together. Grounds are around the grounding screw on the switch. If that was confusing, a photo is here.

Turning the switch on powers both the overhead and the outlet. My guess is the former owners had a lamp plugged in to the outlet and wired this way on purpose. Is there a way for me to pass the power on to the outlet without involving the switch or an electrician? I've done minor electrical repairs/replacements elsewhere in the house, so I'm not completely clueless.

posted by donnagirl to home & garden (16 comments total)

Does it control both plugs on the outlet or only one? If the latter it should be easy to do but will involve replacing the outlet.
posted by TedW at 10:28 AM on January 3, 2008

It controls them both.
posted by donnagirl at 10:30 AM on January 3, 2008

******* I AM NOT A LICENSED ELECTRICIAN. Have a licensed electrician inspect your work. Turn off all power before working on the circuit. *******

The two wires on the right side of the switch in the picture are likely for the light and the outlet.

Disconnect them one at a time to figure out which is which (i.e, pull one off, turn the breaker back on and test the light/outlet). You will need a small screwdriver with a flat blade to get the wire out of the push in socket.

Once you have determined which wire feeds the outlet, you need to attach it to the wire coming out of the other side of the switch. You could do what has already been done and use the screw terminal on the side of the switch. The alternate would be to get another short piece of wire and pigtail the three together, attaching this wire to the switch.

******* I AM NOT A LICENSED ELECTRICIAN. Have a licensed electrician inspect your work. Turn off all power before working on the circuit. *******
posted by davey_darling at 10:39 AM on January 3, 2008

I don't think this a problem that can be solved at the switch. The two devices (lamp, outlet) are probably wired in series. To change it would probably require rewiring the outlet to go directly to the fusebox instead of the switch. I've never done something like that, but I imagine it requires fishing in or tearing-up of the wall.
posted by jeffamaphone at 10:40 AM on January 3, 2008

BTW: I'm just guessing. I don't have any expertise in this area. Davey_Darling seems more informed.
posted by jeffamaphone at 10:41 AM on January 3, 2008

davey_darling (NOT a licensed electrician) had it right. The black wire around the screw controlled the outlet, moving it to the other screw (next to the other black wire) did the trick. It was the red wire that was freaking me out - I couldn't find any wiring diagrams online that included a red wire. Thanks for the quick and easy fix!
posted by donnagirl at 10:53 AM on January 3, 2008

I believe the red, and the white that it's not connected to, are your neutrals, and the switch and the overhead share a common, switched hot; you might want to check in the box closer to the circuit breakers.

Best I can tell, take the black from the screw terminal on the switch and connect it to the other black wire. You can do this by unscrewing it and attaching it to the other screw terminal.

Other note: I hate those little holes, and they may not be code, depending where you live. Any time you take something out of one of the holes, try to put it on some screw terminal.
posted by notsnot at 10:53 AM on January 3, 2008 [1 favorite]

Uh, jeffamaphone, why would they be wired in series? then there wouldn't be 120V to either device!
posted by notsnot at 10:55 AM on January 3, 2008

notsnot, I hate those holes too, because I only have one screwdriver tiny enough to push in the slot, and it's not big or sturdy enough to use to unscrew the switches from the walls, so I need two screwdrivers for one simple job every time. I assumed the holes were an improvement on the screws, since you don't see them on older switches. Interesting to hear they may not be code. I'll probably move the white wire to the screw before I put it all back together, thanks!
posted by donnagirl at 11:03 AM on January 3, 2008

Heh, I may have went a bit overboard on the disclaimer, eh?

Glad it all worked out.

The push in holes are sort of reviled in electrical circles - the amount of time that they save is negligible, and apparently they do not give you as much solid surface contact as a good screw terminal.

I wouldn't worry about switching the white wire to the screw terminal - I mean, great if you do, but on a device such as a light you aren't likely to be drawing enough current to ever have to worry about the connection.
posted by davey_darling at 11:09 AM on January 3, 2008

Here's what I believe was being attempted here. THIS IS ALL SPECULATION AND IF YOU'RE GOING TO LICK ONE OF THESE WIRES MAYBE YOU SHOULD VERIFY THIS WITH A VOLTMETER FIRST OKAY? I'd feel confident in these proclamations if I could back this up with my voltmeter but no matter what, something whacky was done here.

A hot AC wire is black, though some googling shows that the hot wire can also be red or blue. I've never seen this "in the wild" but some entries I find refer to using those colors when in 'series b' which I presume means in cases like this, where something has been done "upstream" of it, like put a switch in.

In your picture they've taken what is presumably the neutral wire coming in from the circuit breaker (I say presumably because it's white, which should be neutral, but given the way this is done coming off the switch I'm not wagering on ANY consistency here) and used a wire nut to connect it to a red wire, presumably going on to either the outlet or the overhead.

In the realm of offenses I'd rather someone connect a neutral wire to a wire colored to give me the impression it's hot, rather than energizing a wire colored to give me the impression it's neutral, but it still sucks.

They've then wired the black (hot) wire to the top of the switch on the outside and used the hole connector to connect it with the white (neutral). Presumably these two wires are going on to different destinations, one the socket and the other the overhead. So it would seem that when the switch is on (it is on in that picture, yes?) they have electrified the white wire in one of those two destinations. This is A Bad Idea, as stated above.

So it looks like they've set this switch up so that when the switch is off (I'm assuming the shown green ground screw is at the bottom/off position of that switch) that both the black and white wires going on elsewhere are disconnected / floating. When the switch is on they are both electrified/hot.

I'd suggest you leave things as they are and get a knowledgeable friend or a proper electrician to look at all three of these locations and correct them so that they are at least no longer energizing wires purporting to be neutral.
posted by phearlez at 11:18 AM on January 3, 2008

phearlez, I agree that it's a little shady, I promise, no wire licking except at parties. My house is a little more than 100 years old, with an addition put on in the late 80's. When I bought the house, one of the conditions of the sale was to have a real electrician update the wiring from knob and tube. The addition obviously didn't have knob and tube, so it was left alone. Since then, I've found a number of weird things in the addition, in the wiring and in the plumbing. Mentioning this to a neighbor, I was told that the contractors for the addition were the former owner's nephews, and they were "jackasses". This confirms my suspicion that the 80s were some sort of nadir of housing construction, as well.
posted by donnagirl at 11:38 AM on January 3, 2008

naaah, right now is the nadir. You wouldn't believe the shit that goes on. Plumbers who don't primer their joints, and wire splices inside conduit are just the iceberg's tip.
posted by notsnot at 12:21 PM on January 3, 2008

When the circuit from the panel goes to the light box first rather than to the switch box first, it is common to have live go from that device to the switch via a black conductor, and return from the switch via a white conductor. In this arrangement, the switch box never gets neutral. This could be extended to a 3-way switch installation by connecting to the switch box with a 3 conductor wire (I'm not sure what the standard colour coding would be for this configuration, the picture is a guess).

So, this could be a situation where there was a 3-way switch, and it has been converted to a single switch in some convoluted way.

Maybe I'm missing another obvious possibility, but it seems to me it is time for a lot of testing and investigation. A non contact voltage detector is very helpful, because you can easily determine which wire is actually live. With everything disconnected and caped off, there should only be one live wire in any single box (well, one live wire from each leg, but you aren't dealing with any 220V stuff in this situation).
posted by Chuckles at 12:59 PM on January 3, 2008

And, in those drawings: dashed line means white, solid pen line is black, green is ground, red is red; I hope 14/2 and 14/3 are obvious, standard 2 conductor and 3 conductor wire, respectively; that funny cylindrical system is supposed to be a light socket - I probably should have been more clear about that :P
posted by Chuckles at 1:06 PM on January 3, 2008

The more I look at that picture the more my head hurts.

I suppose it's possible Chuckles is right and this started its life out as a switch simply interrupting the hot wire to the lamp. Someone decided to add an outlet and ran a red wire down from the light to provide a neutral line, then extended that down to the outlet.

The problem with this theory is (a) why not just run a proper three-wire insulated cable down from the overhead light? and (2) all those wires enter the switch box from the same side, rather than one on top and one set on the bottom.

But who knows when you have that level of insanity in operation? If that's the case - and I would not mess with this w/o my meter, personally - altering the functioning of the outlet to non-switched would simply be a matter of inverting the wires on that switch, resulting in the hot wire coming down from the ceiling always being in contact with the outgoing hot wire for the outlet.
posted by phearlez at 2:26 PM on January 3, 2008