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Joined: Nov 2014
Posts: 2
Y
New Member
2008 Nec 42 circuit max
I was doing some reading into the lift of the 42 circuit max of the nec on an inspectors website which he states his understanding is -

"So the best example I can give to the impact of this change is that I can have a panelboard now with more than 42 circuits except when I am protecting the panelboard with a 2 main circuit breakers or fuses (not a single pole main breaker) upstream of my panelboard where the old rules of 42 circuits would still apply."


I do not want to install a sub panel i am wanting to install a 60 space 60 circuit 200 amp panel .My ?'s -A 200 amp panel technically has a double pole service disconnect main breaker so with this I cannot run a 200 amp panel with 60 spaces that is rated for 60 circuits on that panel? or am I misunderstanding him? If I am misunderstanding when would you have 2 main breakers if they are not referring to the 2 pole main breaker as the exemption? Please clarify for me

Here is the link to the panel I am wanting to use: http://www.homedepot.com/p/Square-D...-Center-with-Cover-QO160M200PC/204246798

Is this panel ok with the main breaker style it comes with under the new 2008 nec guidlines of having more than 42 circuits?

2017 / 2014 NEC & Related Books and Study Guides
Joined: Jul 2004
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G
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There is a misunderstanding here somewhere. I think the person you are talking about was referring to a "lighting and appliance panelboard" and that term is gone too.
The reference to two pole breakers is telling you that a 2 pole breaker counts as two in the breaker count but they removed the maximum so that is moot now.

If you are on the 2008 or newer, that panel you are looking at is legal.

Talk this over with your electrical contractor. He should know if there is some local amendment that changes this.

This is what the code says

Quote

408.54 Maximum Number of Overcurrent Devices.
A panelboard shall be provided with physical means to prevent the installation of more overcurrent devices than that number for which the panelboard was designed, rated, and listed.
For the purposes of this section, a 2-pole circuit breaker or fusible switch shall be considered two overcurrent devices; a 3-pole circuit breaker or fusible switch shall be considered three overcurrent devices.


and this is the handbook commebtary
Quote
Aside from the second exception to 408.36, the maximum of 42 overcurrent devices was deleted for the 2008 Code. Now the quantity of overcurrent devices is limited to design and listing of the panelboard.


Greg Fretwell
Joined: Jul 2001
Posts: 599
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The '2 main breakers' is about panelboards with split bus bars (effectively two sets of bus in one cabinet), not the number of poles on a single breaker.

Joined: Apr 2002
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Made by SqD, UL Labeled, sold at the 'big box'. As stated above IF you are within the 2008 or later NEC, you are good to go.



John

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