Smallest Panel For A Service Panelboard?

[CBean]

Hey you guys, a quick off the subject question. This is an exam question.

I quote "Using full size breakers, a panel with spaces for___________ breakers is the smallest that can be used for a service panel".

What is the 2008 NEC code ref. to this question. I know the max. is 42 NEC 408.15. What is the fewest and where is it found????

 

[charlie b]

You can have a service that consists of a single 15 amp circuit. So my answer would be "one." Reference 230.79(A). I can't think of any other way to answer this question. I strongly suspect that its author has an incorrect understanding of the code.

What is the 2008 NEC code ref. to this question. I know the max. is 42 NEC 408.15.

The 42 circuit limit was removed in the 2008 NEC. It was in 408.35 in the 2005 version, but that pargraph was deleted in the 2008.

Welcome to the forum.

 

[gndrod]

Breaker qty

Breaker qty

I agree with Charlie. The question does not stipulate single or a double pole breaker. The question just basically refers to the Service Panel. A Service Panel can have a single main disconnect which would be one breaker of the required OCPD rating of the panel.

 

[gndrod]

Disconnecting means

Disconnecting means

The Article 225.31 is the minimum single breaker means provided. [230.206] defines the circuit breaker as the alternative disconnecting means.

 

[iMuse97]

I agree with those above; however, I'm wondering if the writer of the exam was thinking of specific limitations which would give a different answer. I've seen many poorly written questions, and suppose that this could be one of them. For instance, did the question mean to say, what are the minimum spaces in a panel that serves a dwelling unit? Around here, there are some jurisdictions where there is a specific answer to that question.

 

[cflava]

A Service Panel can have a single main disconnect which would be one breaker of the required OCPD rating of the panel.

"a panel with spaces for___________ breakers" was the question. I would think that you couldn't count the main disconnect switch because it would not be a space for a branch circuit overcurrent device(NEC 05 408.35 "Not more than 42 overcurrent devices (other than those provided for in the mains"). Technically speaking though, with the previous sentence in mind, a panel would have to have a mininum with a multiple of two since there are two rows. The answer could easily be two.

 

[radiopet]

Maybe they want you to figure out based on the square footage and the 3 VA, as well as the minimum circuits that are required like the small appliance circuits, laundry and bathroom circuits all figured together to come up with a minimum number of circuits that would at least have to be in a panel.....who knows what the author of the question was looking for.

 

[gndrod]

define

define

"a panel with spaces for___________ breakers" was the question. I would think that you couldn't count the main disconnect switch because it would not be a space for a branch circuit overcurrent device(NEC 05 408.35 "Not more than 42 overcurrent devices (other than those provided for in the mains"). Technically speaking though, with the previous sentence in mind, a panel would have to have a mininum with a multiple of two since there are two rows. The answer could easily be two.

Wouldn't two be considered a SE meter main combination then?