Garage & Exterior wiring questions

Discussion in 'Electrical Forum discussion & Blog' started by dgold, Nov 9, 2007.

  1. dgold

    dgold Product R&D for a powertool manufacturer

    Messages:
    82
    Location:
    Carlsbad, CA
    When installing an exterior outlet on my home I need to pass the wire through brick. When installing an additional circuit to my garage, I need to pass wire through block.

    What is the preferred way to do this? Can I just drill a hole and feed interior 14 gauge Romex through the hole? Or do I need to use UF, MC, or conduit? In no case will there be any direct sunlight exposure as I plan to mount the exterior box directly to the wall and feed the wire through a hole in the back side of the box.

    Also, is there any rule regarding the size of the hole? To my garage for instance, I want to run 3-conductor wire through block, in order to add two 110v 20A circuits (one off the black, one off the red). I plan to split them in a junction box to get one circuit down each side of my garage. Then I plan to use a 20A GFCI outlet as the first outlet on each side, immediately after the split, to get GFCI protection throughout -- since as I understand it, I cannot use GFCI breakers with a shared neutral or ground wire.

    Any help is appreciated.
    Thanks.
  2. Mikey

    Mikey Aspiring Old Fart, EE, computer & networking geek

    Messages:
    2,713
    Location:
    Central Florida
    In Florida, I use NM conduit when going through brick or block, mostly to keep the critters out of the boxes. Drill a hole for the conduit, stick a male adapter in the outside box, use plenty of caulk, and fasten the box to the outside wall (Tapcons work well). Put a male adapter in the inside box, cement in a piece of conduit of the proper length, caulk again, put cement on the end of the conduit, push it thru the hole to join up with the outside, and secure the box to the inside wall. Makes a nice clean installation.

    Obviously, the size of the hole is determined by the size of the OD of the male adapters (1 1/8" for 1/2" NM, 1 3/8" for 3/4"). I personally don't like sharing the neutral at all. Using 2 GFCI receptacles is cheaper than a single GFCI breaker, I'm pretty sure.
    Last edited: Nov 9, 2007
  3. dgold

    dgold Product R&D for a powertool manufacturer

    Messages:
    82
    Location:
    Carlsbad, CA
    I've never used the nm conduit before, but sounds a lot like working w/ plastic plumbing pipe. Thanks for the advice.
  4. Speedy Petey

    Speedy Petey Licensed Electrical Contractor

    Messages:
    988
    Location:
    NY State, USA
    Even easier. No cleaner required.
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