||03-27-2008 04:54 PM
Panel Placement In Outbuilding
OK, I've searched all the "garage subpanel" threads I could find, guess I have another to add to the fray:
What (if any) NEC requirements govern subpanel placement within a detached structure? My chief concern is proximity to the garage doors Ė the best location for a panel in my garage (from a ďmost direct feederĒ standpoint) is on a side wall about four feet back from the (vehicular) garage door to the right of the panel, and about two feet away from a window on the left. The back wall of the garage would be the most protected area, but putting the panel there would double or triple the length of all my wire runs (including the feeder and some heavy wire for a welder outlet), and would be very inconvenient from an access standpoint. Is there an issue with placing a panel so close to such a large exterior door? If so, is there any way to mitigate the problem? Also, to minimize the panelís intrusion into the garage space, I had planned on mounting it in a stud bay (the walls are all open), right up against one stud so that the knockout plugs on the other three sides of the box remain accessible. The panel is only serving four circuits so Iím not worried about crowding dozens of cables together on the same side of the box, but I do want to be sure that this isnít somehow prohibited (Iíve seen residential installations where the box was fully recessed into a finished wall, but I'm unsure if I can "classify" this installation the same way).
Also, a more general workmanship question - is it permissible to splice branch wiring inside a service panel? The same conduit that brings the feeder to the subpanel will also bring three #14 THHN wires in from the house for three-way control of the exterior lighting; I'd like to simply bring the 14/3 Romex used for the rest of the circuit right into the panel and splice the travelers together therein. I've read that making splices inside a panel is discouraged because it contributes to crowding, but I should have plenty of space in this install, so I think it's a non-issue, so long as it isn't actually prohibited. If it is, can I at least get away with using the panel as a "pass-through" for the two travelers into another junction box? My planned entry point is close to some diagonal bracing on the wall, and it would be awkward to fit a junction box in to split off the switch wiring before entering the panel.