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Swapping a Switch to a Power Outlet?

  1. Jun 13, 2013 #1

    I was going through the web and was reading about this swap, however I want to make sure on a few questions I still have and was told I could get good advise in these forums.

    So I was gonna go ahead and change a switch for a power outlet for convenience, but then realized it might not be very safe to load it with a power outlet, depending on the circuit the switch is installed to. I am intending to connect a monitor here, the monitor specs say it has a 33Watt consumption.

    There are 2 switches that can operate the ceiling's light bulb in the room, one of the switches is the one I want to replace with a power outlet. I opened up the switch box and I have 3 cables there, a black one, a red one and a white one. I believe the black one and the red one are the phase cables and the white one is the neutral.

    So I have these questions:
    - Is it possible and safe to make this swap?
    - If the safety is questionable, I would have to measure the current present there to make sure? What reading range would I need to have to determine it is indeed safe?
    - If done, will I have to have the remaining switch ON to be able to power the new outlet?

    Thanks so much in advanced for any help I can get on this. :)
  2. jcsd
  3. Jun 13, 2013 #2


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    Certainly sounds like a three way switch. I'm assuming 120 volts.

    33 Watts is next to nothing, the wiring will easily handle this. 14 guage is good to 15 amps. You have roughly .25 amps.

    You have 2 three way switches. One of those switches has power coming from the breaker panel and the other switch has power coming from the first switch.

    If you want the power outlet from the "breaker panel" switch, then a simple parallel connection is an easy "jump" away. Just grab the line and neutral...plus ground. Pretty sure you can buy an outlet that has a three way switch built into it.

    If you want it from the "other" switch, you need to reconnect the wiring at the "homerun" switch to be "hot" all the time to the "other" switch. Line to neutral. Actually, at this point you will need to just remove the "homerun" three way switch.

    Then the "other" switch will now have 120 volt all the time to it. You can now wire your outlet off this and the switch for your light will have to be at this same switch. You can also connect your outlet to be switched as well.

    Complicated I know....but what I'm saying should be about right....and you will see it is fairly easy once you figure it out.

    You might want to study up on three way switches here:

    Incidentally, although your three ways have 2 line phases and a neutral......the actual power going to the homerun three way is just line to neutral. That extra phase leaving that switch to the "other" three way just gives an alternate current path which you will read about in links above.
    Last edited: Jun 13, 2013
  4. Jun 13, 2013 #3
    I think what you are trying to communicate is that you have existing wiring for a two switch light control, whereby a room light can be turned on and off from two locations... Here's a page with two possible schematics for such a beast: http://www.electronics-project-design.com/LightSwitchWiring.html And you want to change one of the switches to an outlet to run a computer monitor.

    Two problems... If your wiring is like the second schematic, only one of the switch boxes has the "hot" wire you need to run your outlet -- labeled "LIVE" at the little sine-wave-source on the left (if you have wiring like the first schematic both boxes have a hot wire -- connecting the "L1" switch poles, so you could be OK). BUT there may not be a neutral wire in your switch box at all since there is no need for one in either schematic. So you may not have the two connections you need to power an outlet.

    The only way to tell is to go in with a test light or meter and try all the combinations of wires and switch positions. But since you had to ask this question, I have the feeling that you are not experienced enough with electrical thingies to be able to do this safely. Do you have a friendly electrician in your neighborhood who could assist you?
  5. Jun 13, 2013 #4


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    I would agree that you can't really "guess" this stuff.

    If you wire it wrong, there is always a chance for a fire. That being said, make sure you have someone smarter than you (experienced electrician preferably) to check your work before turning power back on.

    Since your monitor is only .25 amps....you may just want to consider running an extension cord:-/
    Last edited: Jun 13, 2013
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