Hot Topics: Sub Panel Diagrams

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For the complete diagrams, see the original piece - Sub Panel Diagrams

ray2047 - Member

The term sub panel does not appear in the NEC but for convenience we use it to refer to any panel other than the panel containing the first OCPD (Over Current Protection Device). Below are three of the most common for subpanels not in the same structure and one for a subpanel in the same structure. The first four diagrams are based on 2008 NEC code.

The fifth diagram is based on NEC code before the 2008 cycle assuming no other metallic pathways. It is usually grandfathered unless major changes are made. What is a major change is determined by the Authority Having Jurisdiction (AHJ).

sub panel diagram 1

sub panel diagram 2

sub panel diagram 3

sub panel diagram 4

sub panel diagram 5

120 volt 30 amp RV panel using 240 volt Main Lug panel.

sub panel diagram 6

TRANSFER SWITCH With sub panel connected to first OCPD and inlet.

sub panel diagram 7

Zorfdt - Forum Topic Moderator

Very helpful drawings Ray! They have been and will be quite useful.

Good luck... what's the worst that can happen?

gman23 - Member

I was wandering why the diagram on main panel & sub panel on same structure has no ground rod & marked no ground rod? It is the 4th diagram down...

ray2047 - Thread Starter

Code (NEC) does not require ground rods for sub panels in the same structure.

gman23 - Member

I see what you mean! The ground is on main panel! That make sense.

Thanks again for the great info!