408.36(B) 2005 cycle

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DavidA

DavidA

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If a panelboard doesn't contain a neutral with it's supply conductors (supplying only 3 phase motor loads) is it still considered a power panelboard? Does it still need OCP as specified in 408.36(B) 2005 cycle? Or since there is not a neutral to this board is it now classified as something else?
 
My understanding is, with the rewriting of 408.36, there are no longer "power" and "L&A" panels and all must meet the requirements of that section.
 
augie47 said:
My understanding is, with the rewriting of 408.36, there are no longer "power" and "L&A" panels and all must meet the requirements of that section.
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I agree, the distinction between lighting and appliance panelboards and power panelboards was removed from the the NEC in 2008. Now all panelboards must be protected by a single overcurrent device with a couple of exceptions.

Chris
 
DavidA said:
If a panelboard doesn't contain a neutral with it's supply conductors (supplying only 3 phase motor loads) is it still considered a power panelboard?
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Yes, that would still be a power panelboard. A power panelboard has 10% or fewer "lighting and appliance branch circuits." Lighting and appliance branch circuits is a branch circuit that has a connection to neutral, therefore, you panel would have zero lighting and appliance branch circuits.

DavidA said:
Does it still need OCP as specified in 408.36(B) 2005 cycle? Or since there is not a neutral to this board is it now classified as something else?
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No it does not need the OCP as specified in 408.36(B). That OCP would be required on a power panelboard with a neutral supply conductor.... Since your power panelboard doesn't have a neutral supply conductor, 408.36(B) would not apply.
 
It just struck me as odd that the inclusion or exclusion of the neutral conductor would determine if protection was required or not. Figured I'd better go for a second opinion. Thank you.
 
DavidA said:
It just struck me as odd that the inclusion or exclusion of the neutral conductor would determine if protection was required or not. Figured I'd better go for a second opinion. Thank you.
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Well its not ONLY the inclusion of the neutral, but inclusion of the neutral AND having more than 10% of its branch circuit OCPDs rated 30A or less.

Having no neutral would preclude the need for an OCPD to protect the panel, but having a neutral and no 30A or less branch circuits would also preclude the need for an OCPD to protect the panel.
 
That makes sense. I had zeroed in on the neutral portion and neglected the minimum branch circuit size when I was reading through this portion. Trying to understand the NEC can be very frustrating at times.
 
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