MN-B, 12-3/GRD inside 2" PVC conduit

Discussion in 'Electrical Forum discussion & Blog' started by Ford2001, Sep 19, 2009.

  1. Ford2001

    Ford2001 New Member

    Messages:
    44
    Location:
    Manchester, Vermont
    Thinking about using 2" PVC conduit attach to the top of circuit breaker
    panel. The conduit would run up the side of the wall, (note: panel is surface
    mounted), then 90 over to the center of the room, where the opposite end
    would terminate inside a large j-box. Something like a 6x6x4.

    Yes I know thhn individual conductors would work better. But it's money
    thing. Have the romex cable left over, and just want to be sure this
    nothing the NEC code that would prohibit this practice.



    And how exactly do you measure the dia. of 12-3 romex?

    Thanks to all who show an interest and reply.
  2. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    There are code issues about putting NM cable in conduit. The ratings of the cable are based on it being in free air. But a 12-3 would FIT inside ½" conduit! What's up with running 2" conduit in your ceiling???


    What do you mean by "how do you measure the size of 12-3??""??
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    26,240
    Location:
    Cave Creek, Arizona
    ?

    What are you trying to do? 2" conduit seems like overkill for a single Romex wire, and if you are running a lot of them the J-box may not be the right choice.
  4. Ford2001

    Ford2001 New Member

    Messages:
    44
    Location:
    Manchester, Vermont
    romex cable in a 2" PVC conduit

    The 2" PVC conduct witll be a continuous run from the top of the
    electrical circuit breaker panel box, to were it connects with a large
    j-box, something like a 6x6x4.

    The ceiling will be unfinished, open raftiers. There are no plans, at this
    time to finish the ceiling.

    The area in question, is in a seperate building. That is currently used
    only for storage. This building never had power.

    My plan, is approved, will be to run, four individual, 12-3 NM-B cable
    thru the 2" conduit. This can give four, 120 volt, at 20 amps. circuits.

    Also, is the old timer needs a 240 volt circuit I will be able to supply that
    as well.

    Thanks for your previous replies.
    Last edited: Sep 19, 2009
  5. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Well, you may have code issues with 4 nm inside conduit. You will need to find out from your inspector if that is allowed. Speedy Petey is one of our NEC experts, so hopefully he will come along and give you an expert answer.
  6. Jim Port

    Jim Port Electrical Contractor

    Messages:
    156
    Location:
    Maryland
    Since you are planning for a junction box already just run individual THHN conductors. Much easier to work with and it leave more space in the conduit.
  7. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
    The main isse is that the NM won't be connected to the panel box.

    Here, it would be a non issue.

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