408.36(B) 2005 cycle

[DavidA]

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?

 

[augie47]

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.

 

[raider1]

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.

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

 

[david luchini]

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?

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.

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?

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.

 

[DavidA]

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.

 

[david luchini]

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.

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.

 

[Pierre C Belarge]

I believe part of the reasoning is these types of installations will most likely be found where there are qualified people working there.

 

[DavidA]

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.

 

[Hendrix]

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.

You aint just a whistlin' dixie.:grin:

 

[jumper]

Trying to understand the NEC can be very frustrating at times.

All so true, I swear it drives me bonkers at times.