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View Full Version : NEC and Electrical Control System Back Boxes



AudibleSolutions
06-07-2005, 12:51 PM
This is a problem I suspect few of you encounter as you probably work in single Family homes with both basements and attics. Here in NY space is at a premium and we are often asked to place electrical back boxes in some strange places.

What is code with respect to lighting control system back boxes. Where can and can they not be placed? Can they be placed in closets? Are they considered the same as service panels or splice boxes?

Alan

ssamsal
06-07-2005, 05:34 PM
This i'm sure you know as you deal with it all the time, but the things I'm dealing with here are in regards to demising walls and are the outlets packed and go through the acoustical contractors rating system. The only thing here people are worried about is getting sued for sound transmission problems.

Doesn't really answer your question Alan, but something to take into consideration.

AudibleSolutions
06-08-2005, 09:47 AM
Ironically, that turns out not to be a big issue here in NYC where concrete block and brick is not atypically what the walls are constucted. New building code requiring all penitrations through floors must be filled with fire retardant foam is a problem, especially as I always forget to carry it in the truck.

Larry, what is the decision on high voltage back boxes in closets? Or am I again allowed to post answers to my own questions?

Alan

jritch
06-08-2005, 09:59 AM
I don't know about high voltage in general, but some municipalities here don't allow outlets in closets. It's referred to as the 'Hydroponic Clause'...

AudibleSolutions
06-08-2005, 03:11 PM
Larry doesn't seem to wish to play any more. Wah, wah. We shall try to answer our own question although it has not been completely figured out. The relavent passage from 2005 NEC seems to be 408.38 but before I go into it I'd like a chance for the really smart folks to respond ( as in the a few EE's ).

Alan

LarryFine
06-18-2005, 11:41 PM
Sorry, guys, I've been so busy that I hardly have time to play in the forums.

Alan, I don't understand the question. What do you mean by "back boxes"?

AudibleSolutions
06-20-2005, 08:20 PM
Back boxes for power modules in centralized dimming systems. Feeds and switch legs are attached to DIN rails in the back box and modules attached to the DIN rails. Lutron Homeworks, Lightouch, Vantage, Crestron all make panels for centralized lighting systems.

Alan

LarryFine
08-15-2005, 08:59 PM
I'm baaaack! Sorry about the absence, especially Alan! I had no idea I'd be missed that much. Also, you may answer your own questions any time you like.

Okay, in case anyone is still interetsed, now that I know you mean a box with no (or no significant) front-panel devices, they can go almost anywhere.

I'd avoid bathrooms and other obvious places, but otherwise, almost anywhere is okay; closets, hallways, attics, etc., with the following in mind:

The code requires a space 30" wide or the width of the cabinet, whichever is greater, and 3' from the panel to the opposite wall, behind the technician.

Again, sorry about the delay in responding. As Superman said: "Sorry, Mr. President; it won't happen again!"