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Thread: Maximum number of oc devices in a panel ?

  1. #1
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    Maximum number of oc devices in a panel ?

    I'm trying to determine how many oc devices in a panel board. (I think it changed years ago ??)
    research shows 408.15 at 42...... but thats gone...........

    I've read prior to I think panels of 2008 it's 42. newer panels it's to what ever the manufacturer rates it for....... 60......80 ??? where is this?

    I do see though, if I have this correctly, 408.36 exception 2 is saying main lug panels protected by circuit breakers or fuses are limited to 42 circuit max.... is this correct?
    " I'm at a crucial part of my painting "...........Monika Danneman

  2. #2
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    The limit of 42 spaces in a panel was removed a few years ago. To my knowledge nobody makes a gfci or afci breaker tandem, mini, or half size, whatever you call it so you are still limited by that.

    Afaik, there are no 2-pole AFCI / GFCI breakers that use just one space either.

    Eta : I would probably use two panels rather than one if I needed more than 42 circuits
    Electricians do it until it Hertz!

  3. #3
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    Didn't even consider the af gf aspect of it....... so you're saying to the best of your knowledge the panels that are rated for 60 or more circuits still have 42 actual space spots ??
    " I'm at a crucial part of my painting "...........Monika Danneman

  4. #4
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    Quote Originally Posted by ritelec View Post
    Didn't even consider the af gf aspect of it....... so you're saying to the best of your knowledge the panels that are rated for 60 or more circuits still have 42 actual space spots ??
    to my knowledge, some of the panels achieve a higher number of Breakers by using split or tandem Breakers, others have full size breaker spaces for all positions, and a proportionate increase in size
    Electricians do it until it Hertz!

  5. #5
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    Quote Originally Posted by JFletcher View Post
    to my knowledge, some of the panels achieve a higher number of Breakers by using split or tandem Breakers, others have full size breaker spaces for all positions, and a proportionate increase in size
    thank you
    " I'm at a crucial part of my painting "...........Monika Danneman

  6. #6
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    42 circuit rule applied to what NEC called "lighting and appliance panelboards" at that time. To meet that definition it had to have (from recollection) 10% or more of the connected load supplying 30 amp or less line to neutral loads. This made most "loadcenters" you ever ran into fall into that description. If you were only supplying line to line loads or over 30 amps when a neutral was involved there was no 42 circuit limit - but they didn't really make any with more then 42 spaces either because there just wasn't a demand for them.

    Now that that rule is gone there is no limit. But an old panel will still have a maximum number of circuits it was designed and listed for and that still applies. It is newer panels that will be where you see design and listing for more then 42.

    I have installed NQ 84 circuit (full size no tandems) panels before -with 400 amp main breaker kit installed - the cabinet was around 7 feet tall from what I recall.
    I live for today, I'm just a day behind.

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