42 Circuits or Not?

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donburde

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Fort Lauderdale, FL
I have heard several people mention that you are able to use more than 42 overcurrent devices in a panelboard as long as that panelboard is not a lighting and appliance panelboard and/or not more than 5 of these overcurrent devices are single pole breakers. It has been said to me that it is ok to use a 54 circuit panel board in certain situations under the 2005 NEC. I have spent hours looking for this in the 05 code book. can someone tell me if this is correct and if so, please tell me in the code where it states this. I know it says only 42 in 408.34 and 408.35 but i cant find anywhere where it says you can use more than 42 in ANY situation. Can someone please advise? Thanks!!
 
I thought square D made a 52 breaker panel, but I also thought I read here that it was under review, Bust it out - add a sub-panel.
 
well yes... under the 2008 code i believe this 42 breaker limit has been eliminated so im sure we will see all kinds of high volume breaker panels...but im looking for an article in the 05 code
 
Unless you can sweet-talk your inspector into letter you get by with it, if you're wiring under the '05, you still have the 42-circuit limit to contend with. 408.35 was deleted in the '08.
 
Look at 408.34 and 408.34(B) in the 2005 NEC for the definition of a Power Panelboard. If you panel meets that criteria it does not have the 42 circuit limit listed in 408.35.
 
donburde said:
I have heard several people mention that you are able to use more than 42 overcurrent devices in a panelboard as long as that panelboard is not a lighting and appliance panelboard and/or not more than 5 of these overcurrent devices are single pole breakers.
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There is no such animal in the 2008 code. The 2008 NEC does not mention lighting and appliance branch panelboards.
 
infinity said:
Look at 408.34 and 408.34(B) in the 2005 NEC for the definition of a Power Panelboard. If you panel meets that criteria it does not have the 42 circuit limit listed in 408.35.
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In 2008' none of those article numbers exist and have been bulleted...
(for all you playing along)...
 
cadpoint said:
In 2008' none of those article numbers exist and have been bulleted...
(for all you playing along)...
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Darn, I missed the shoot-out!
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Canada has had 84 circuit panels for many years. While we no longer have the 42 circuit limit in the NEC, it will take some time for product standards to be updated and product to be available.
 
i still feel uncomfortable with some of these answers, for example the one given by Member infinity - "Look at 408.34 and 408.34(B) in the 2005 NEC for the definition of a Power Panelboard. If you panel meets that criteria it does not have the 42 circuit limit listed in 408.35." So I am to interpret this as, I can have AS MANY overcurrent protection devices as I want? This doesnt make sense either. Hypothetically speaking, if there were a panel that consisted of 168 spaces, this would be legal(of course assuming that there wasnt any lighting or appliance circuits)? That cant be correct, I could be wrong but it sure doesnt seem right to me IMHO...
 
donburde said:
if there were a panel that consisted of 168 spaces, this would be legal(of course assuming that there wasnt any lighting or appliance circuits)? That cant be correct, I could be wrong but it sure doesnt seem right to me IMHO...
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I believe that is correct and I believe there have been some commercial panels that consist of more than 42 circuits.
 
donburde said:
i still feel uncomfortable with some of these answers, for example the one given by Member infinity - "Look at 408.34 and 408.34(B) in the 2005 NEC for the definition of a Power Panelboard. If you panel meets that criteria it does not have the 42 circuit limit listed in 408.35." So I am to interpret this as, I can have AS MANY overcurrent protection devices as I want?
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Under the 2005 NEC or before yes that is exactly what it means, but read the definition of power panel panelboard and you can see that would be pretty rare to have a power panel panelboard with that many circuits.

Hypothetically speaking, if there were a panel that consisted of 168 spaces, this would be legal(of course assuming that there wasnt any lighting or appliance circuits)?
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Correct.

That cant be correct, I could be wrong but it sure doesnt seem right to me IMHO...
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It is correct and I see no reason it should not be.

Now under the 2008 NEC there is no limit whatsoever to the number of overcurrent devices, if a manufacturer makes a 500 circuit panel and UL lists it we could install it.


mxslick said:
quogueelectric said:
If you are allowed 84 receptacles on one ckt why not 84 ckts on one panel??
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Two words:

Heat buildup:smile:
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More words:

Careful design. :smile:
 
Here is a link to a Square D PDF that outlines their new line of panels that comply with the 2008 NEC.


There are some jurisdictions that have adopted the NEC and permit these types of panels to be installed, and there are many that have not.

NYS division of codes department sent me an email stating that these panels are not permitted in the state. They are evaluating the situation and will have a ruling by the next State code cycle.
 
I have installed power panelboards used with all 3 pole CB's that had more than 42 slots. They were for a conveyor system. Under the 2005 or earlier codes a panelboard that met the definition of a power panelboard had no circuit limitation.
 
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