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15 amp sockets and code?

Discussion in 'Electrical Engineering' started by [email protected], Jun 11, 2008.

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  1. Guest

    Yesterday I got a call from someone asking about how to
    wire up some sockets and lights in a basment remodel.
    The specific question was about the breaker size since
    the box the outlet came in specified a 15A breaker.
    I asked what guage wire he was running and since it was
    14ga told him to use 15A breakers.

    Now the question. Has the code changed in recent years
    to disallow 15A (NEMA 5-15) outlets on 20A circuits, assuming
    of course the circuit uses 12ga wire? I know there used
    to be specific exemption for 15A rated outlets on 20A wiring.
    Have they taken that away, or was warning on the box some
    legal CYA? Just curious.

    Bill Ranck
    Blacksburg, Va.
     
  2. James Sweet

    James Sweet Guest


    I always use 20A circuits and #12 wire for receptacles, it's been
    standard practice for decades. The 15A rating is for each individual
    section of a duplex receptacle, no appliance with that plug will draw
    more than 15A.
     
  3. Guest

    Well, that's my standard practice as well. The question was about
    the warning/instruction on the outlet packaging that specified
    use of a 15A breaker. First I'd ever heard of such a warning.

    I told the guy I would normally use 12ga wire, but he already had
    14ga and as far as I know it's not illegal to use, just not what
    I would do.

    Bill Ranck
    Blacksburg, Va.
     
  4. James Sweet

    James Sweet Guest


    Maybe they're super cheap receptacles? Amazes me whenever I see someone
    installing the 79 cent things when $1.60 or so will get one so much
    better made that doesn't wear out in a few years.
     
  5. Guest

    On Wed, 11 Jun 2008 17:53:17 +0000 (UTC) wrote:

    | Yesterday I got a call from someone asking about how to
    | wire up some sockets and lights in a basment remodel.
    | The specific question was about the breaker size since
    | the box the outlet came in specified a 15A breaker.
    | I asked what guage wire he was running and since it was
    | 14ga told him to use 15A breakers.
    |
    | Now the question. Has the code changed in recent years
    | to disallow 15A (NEMA 5-15) outlets on 20A circuits, assuming
    | of course the circuit uses 12ga wire? I know there used
    | to be specific exemption for 15A rated outlets on 20A wiring.
    | Have they taken that away, or was warning on the box some
    | legal CYA? Just curious.

    It could be CYA. Or it just could be a simple error by the writer
    of those instructions.

    The code has not changed with respect to the outlets. You can use
    15A style outlets on a circuit protected with a 20A breaker so long
    as there is at least 2 such outlets on that circuit. The biggest
    question is the size of wire. If it is #14 CU then it needs to be
    protected at the 15A level and then no 20A style outlets are allowed.

    If the wire is #14 CU then the breaker must be 15A and the outlet or
    outlets must be 15A.

    If the wire is #12 CU and there is only one outlet, 15A or 20A, the
    breaker and outlet must be the same rating.

    If the wire is #12 CU and there are multiple outlets, a 15A breaker
    may be used but only with 15A outlets (no 20A outlets).

    If the wire is #12 CU and there are multiple outlets, a 20A breaker
    may be used with any mix of 15A and 20A outlets (including only 15A
    outlets).

    I don't really see a reason having a 20A breaker on a #12 CU circuit
    with a single 15A outlet is a safety hazard (since the appliance would
    not use more than 15A and if it did, the wiring is rated for 20A and
    the breaker woukd trip above that). But the code currently does not
    allow that.

    Apparently, all 15A outlets are capable of handling 20A, at least in
    the common part. The 20A plug has the same contact surface area as
    a 15A plug, so I don't see that this is the issue. If UL tests all
    outlet devices that are of the NEMA 5-15R configuration as if they
    were of the 5-20R configuration, and they pass, it should be safe.
     
  6. Guest

    Thanks for the very complete answer, Phil. I have forwarded it
    on to the guy who was asking me about it, and except for the
    restriction dealing with a single outlet on a circuit was pretty
    much what I remembered. I wonder how many 20A breakers are
    technically in violation on fixed appliance circuits out there?
    Although, I guess a duplex outlet doesn't count, and I bet most
    of them are duplex.

    Bill Ranck
    Blacksburg, Va.
     
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