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Thread: Switch Size??

  1. #1
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    Switch Size??

    This switch is feeding the 800A board with 2 sets 4" w/ 4#500's. 400A fuse is throwing me off as not enough to feed 800A panel and protect the feeders although they show two fuses..weird?? Thanks.
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  2. #2
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    Read this. Similar thread, may help.

    http://forums.mikeholt.com/showthread.php?t=163274
    "Electricity is really just organized lightning." George Carlin


    Derek

  3. #3
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    It certainly appears that from the way it is drawn someone has two 400 amp fuses in parallel to get the 800 amps.
    Last edited by infinity; 08-08-18 at 03:30 PM. Reason: Fixed Number
    Rob

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    All responses based on the 2014 NEC unless otherwise noted

  4. #4
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    Sorry, misread question, thought you were asking IF 400A fuses could be put in a 800A rated switch.

    I got no clue about that paralleling of fuses. Did not really look at first time.
    "Electricity is really just organized lightning." George Carlin


    Derek

  5. #5
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    Parallel only allowed per NEC 240.8

    Yes, you can get 400A Class L fuses.
    "Just because you're paranoid, doesn't mean they're not out to get you"

  6. #6
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    Quote Originally Posted by kingpb View Post
    Parallel only allowed per NEC 240.8

    Yes, you can get 400A Class L fuses.
    Cool.
    "Electricity is really just organized lightning." George Carlin


    Derek

  7. #7
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    Quote Originally Posted by jumper View Post
    Sorry, misread question, thought you were asking IF 400A fuses could be put in a 800A rated switch.

    I got no clue about that paralleling of fuses. Did not really look at first time.
    np

  8. #8
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    Quote Originally Posted by infinity View Post
    It certainly appears that from the way it is drawn someone has two 400 amp fuses in parallel to get the 800 amps.
    Isnt a fuse needed for each phase conductor?

  9. #9
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    Quote Originally Posted by mstrlucky74 View Post
    Isnt a fuse needed for each phase conductor?
    Read the reference posted earlier. Stuff has to pre-qualified by manufacturers.
    "Electricity is really just organized lightning." George Carlin


    Derek

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