Wiring a dimmer for outlet use

September 16, 2009 9:57 AM

Basic wiring: can I put a clamp light on a dimmer? I want a cheap means of fading in and out lights for my makeshift light kit. The dimmer I bought only has one pair of wires, plus an extra red wire and a green ground. I want to send power in and out of the dimmer. Is this possible? Photos inside.

http://img441.imageshack.us/img441/1069/dimmer1.jpg
http://img441.imageshack.us/img441/1016/dimmer2.jpg

posted by davidriley to home & garden (6 comments total)

You want an inline dimmer which won't have a ground wire and doesn't need a box.
posted by oneirodynia at 10:01 AM on September 16

Not sure what the wiring of the dimmer switch is, but the one thing I noticed is that your proposed cable and plug aren't grounded. Please seriously consider changing to a 3-prong grounded plug and cable, and connect the ground wire to both the metal box and to the green wire of the dimmer. The 2-wire ungrounded cable to the light socket can stay as is.
Also, if you'll be using this rig outside, plug the whole deal into a GFI protected outlet, if at all possible.
posted by rocket88 at 10:09 AM on September 16

Do you have instructions for that switch?

That doesn't look like a standard dimmer switch, which would only have two or three wires. If I had to guess I'd say you have a three-way switch, which is generally used in situations where there are two switches controlling one light.

To answer your question, yes you can control a clamp light with an incandescent bulb on a dimmer, but I'd suggest you go to the hardware store and purchase a switch with two wires, or use an inline dimmer as oneirodynia suggested above.
posted by SteveInMaine at 10:18 AM on September 16

yeah, sounds like the one you have could be a "digital" dimmer or some other sort that uses runners to signal between dimmers... or could simply be a three-way dimmer.

(can't look at images from work to see)

dimmer is fine on an incandescent bulb in any sort of socket... and they sell all sorts of slide dimmmers, dial dimmers, inline shapes and forms at standard hardware stores... you want a simple dimmer that gets place inline with the "hot" wire... the hot gets cut and the dimmer gets connected to the two ends you've made at the cut.

dimmers don't always like GFCI and vice-versa... but they can't (generally) hurt. The Ground Fault Circuit Interrupter "checks" multiple times per second/millisecond to see if there's a short (a load much larger than the circuit can expect/handle) and interrupts if need be. Wiring these is relatively easy... you can even find male plugs with them built in or just buy a short extension cord that has one built in if you're worried about using it near water or where the wire might get cut/poked/split.

Really, as long as you know how to wire a simple light switch (or make your own extension cord), you can do this w/o a GFI/GFCI and without electrocuting yourself (just make sure it's not plugged in while you're wiring it). And follow the instructions in the package with the one-way dimmer.
posted by Jiff_and_theChoosyMuthers at 11:22 AM on September 16

The wires coming out of this dimmer are not so odd. The green wire is for grounding to the box and to the ground wire from the plug (which you don't have). The black connects to the "hot" wire that goes to the plug. The unlabeled red wire goes to one side of the socket. The red wire that has a label on the end is for use in 3-way switch setups, so you will not use it. The 2nd wire from the socket gets connected to the "common" side of the plug wire.

You need to obtain a 3-prong plug and a length of 3-conductor (2+ground) wire (flexible, with stranded conductors; not romex) to go between the plug and the box. The 3 conductors will be green, black and white. The black wire is the "hot" side and gets connected to the brass terminal inside your 3-prong plug. The white wire is the "common" side and gets connected to the silver terminal in the plug. The green or bare wire is the ground, and connects to the green terminal in the plug. Remember, the other end of the green wire gets connected to the green wire on the dimmer AND to the box itself.
posted by jon1270 at 11:42 AM on September 16

I have my table lamp on a Westek 4010 dimmer. Using something like that will save you a lot of wiring effort, as your lamp just plugs on in. Also saves you building some sort of enclosure for the wall-nount dimmer you've got now.
posted by Wulfhere at 1:43 PM on September 16