Help With Wiring a Dimmer Switch to an Extension Cord

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Old 02-22-11, 07:53 AM
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Help With Wiring a Dimmer Switch to an Extension Cord

Hello Everyone!

I decided to take on a project which requires me to wire up a dimmer switch to an extension cord. I followed the instructions which were posted on this website, but it didn't work. I'm trying to wire the dimmer switch to a 3 prong extension cord. Before we continue, I know a product already exists that satisfies my needs (in line dimmer) but I found that out after I purchased my supplies, and what fun would life be if everything was that easy?

Here's what I did initially:
  1. Cut the 3 prong extension cord in half
  2. Separated the wires and stripped about 3/4 inches off of each to expose copper
  3. Took the green wires from both ends of the cord, and intertwined them w/ the green wire from the dimmer, capped with wire nut and then electrical tape
  4. Connected (what I thought was) the two neutral wires from each cord and wired them up, capped, and then taped
  5. Then took (what I thought was) the two hot wires, and wired them up to the black wire connected to the dimmer, capped, and then taped
I plugged it in to try it out and... NOTHING. Strangely this extension cord dimmer hybrid worked exactly like an extension cord. When the dimmer was in the off position, my electronics worked like normal. The full amount of power was also going to these electronics no matter what position the dial was in.

I then assumed that I incorrectly appropriated which wire was neutral vs. hot so I undid the neutral and hot wiring and switched them. Tried the extension cord out again and... SAME THING. Works great as an extension cord, but not as a dimmer .

FYI, the dimmer had one black wire coming off the top, and a black wire and green wire coming from the bottom. If anybody can help I would greatly appreciate it. Take care.
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Old 02-22-11, 07:58 AM
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Ok I'm an idiot. I was supposed to wire the two hot wires to the two black wires from the dimmer SEPARATELY. Sorry for wasting space on the website .
Old 02-22-11, 10:52 AM
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Depending on what that cobbled up device is used for, it could be very unsafe and a fire hazard. There are several safety modifications that should be included such as the use of a grounded plug* and cord, quality cord, proper box clamps and cord fittings, an inline fuse and GFCI protection. Furthermore, that type of dimmer can only safely supply incandescent lamps or similar resistance elements. Other types of load will be damaged by the dimmer.

* I see you did that, but the instructions do not indicate it.

The reason that method is cheap is that it is not safe.
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