Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Basic home GFI outlet question

  1. Jun 7, 2010 #1
    If I have just a regular a GFI like this: http://www.ehwms.com/images/Electric/GFI%20Outlet.jpg [Broken]

    I can power each of the two sockets individually by bringing each it's own power line and neutral line, right? (this is what I want to do -- I'm using GFIs for a project (non-electrician home electrical type stuff)

    Or are they both powered by one power and one neutral line?
     
    Last edited by a moderator: May 4, 2017
  2. jcsd
  3. Jun 7, 2010 #2

    berkeman

    User Avatar

    Staff: Mentor

    They are both powered by the same Hot/Neutral line pair.
     
    Last edited by a moderator: May 4, 2017
  4. Jun 7, 2010 #3
    damn. thanks.
     
  5. Jun 7, 2010 #4

    berkeman

    User Avatar

    Staff: Mentor

    What you might be thinking of is that some GFCI outlets have a Hot/Neutral In, and a Hot/Neutral Out. The Hot Out is switched by the GFCI mechanism, so you can protect downstream outlets with the single GFCI unit. You label the downstream (regular-looking) outlets as GFCI protected, and if the downstream outlets stop working, you have to remember to go reset the single FGCI outlet switch.
     
  6. Jun 7, 2010 #5
  7. Jun 7, 2010 #6

    berkeman

    User Avatar

    Staff: Mentor

    AFAIK, the duplex plugs will always be powered in parallel. Even if they seem to have two sets of Hot/Neutral contacts, that is just to facilitate daish-chaining them.

    What is your application? Why do you want to power them indepently?

    Note that there is a safety reason to not power the two sockets in a duplex outlet from different Hot/Neutral feeds. Can you think of the problem?
     
  8. Jun 7, 2010 #7
    Thnx for the info!


    I'm actually trying to build a little project for stage lighting (for my band) where you'll be able to plug in up to four different color lights, and they'll each be independently be controlled (turned on / off) by a microcontroller....so this isn't for a home application. I'm looking for some easy kind of electrical outlet/receptacle (4 of them) that I can independently control and fit neatly into a project box. I was thinking of using two duplex plugs, but I guess I can't control each plug independently.

    And out of curiosity, what is the safety problem with powering both independently?
     
  9. Jun 7, 2010 #8

    berkeman

    User Avatar

    Staff: Mentor

    Ah, good. The safety issues comes from having what you thought was an outlet that you locked out at the breaker box, but the other outlet is still powered! Yikes.

    I'd recommend using single outlets like the one shown in your latest link. That should be a pretty clean solution.
     
  10. Jun 7, 2010 #9
    Ah ok thanks! Do you know of any good enclosure/box that could fit four of those in a row in it and would still be easy to drill holes into ?
     
  11. Jun 7, 2010 #10

    berkeman

    User Avatar

    Staff: Mentor

    At the hardware store, you can buy the outlets, as well as metal "junction boxes" that they mount in. You can get them 2-wide and 4-wide, and it sounds like you would want the 4-wide junction box. You can get facades for the junction boxes that give you a clean front appearance.

    Be sure to ground the metal box with the ground leads that come in with your 4 power cords. There are ground screws in the metal j-boxes to accommodate this grounding safety feature.
     
  12. Jun 7, 2010 #11

    berkeman

    User Avatar

    Staff: Mentor

  13. Jun 7, 2010 #12
  14. Jun 8, 2010 #13

    MATLABdude

    User Avatar
    Science Advisor

    Maybe it's just in my neck of the woods, but there's often a tab on the side that links the top and bottom live and neutral wires. You can snap this off to facilitate split duplex wiring for the hot leg (in kitchens), and I *believe* this is the case for the neutral as well (but you'd be better off verifying with a continuity meter).

    However, the ground conductors will still be linked (so you may end up with ground loops, if this is a concern...)
     
  15. Jun 8, 2010 #14
    I actually intend on connecting all the grounds and neutral together, so this might work out well. The hot is the only one i want to turn on and off independently among all the outlets with relays.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Basic home GFI outlet question
  1. Home wiring question (Replies: 2)

Loading...