Bob Clukey
Member
I have been trying to locate the minimum space required above a 2 x 4 drop in fixture in a suspended ceiling. Any help would be greatly appreciated.
Space above Flourescent Fixture
- Thread starter Bob Clukey
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I have never seen a requirement for space above a fluorescent.
muskrat
Member
- Location
- St. Louis, MO
Don't have NEC handy but I think it has to do with proximity to combustables/surface mnt ?????? 1/4 inch
Last edited:
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
410.115(A) states that the recessed fixture shall be installed so that adjacent combustible material will not be subject to temperatures above 90C.
kwired
Electron manager
- Location
- NE Nebraska
With magnetic ballasts we used to notice that if thermal insulation was installed directly on top of luminaires that there seemed to be more ballast failure likely due to less dissipation of heat because of the insulation. No real study done on this just seems that places that had insulation installed that way had more service calls requiring ballast changes.
Not sure if similar problems appear with electronic ballasts. I have not run into many luminaires covered in insulation that had electronic ballasts in the first place.
NEC does not address it other than what Dennis mentioned.
Not sure if similar problems appear with electronic ballasts. I have not run into many luminaires covered in insulation that had electronic ballasts in the first place.
NEC does not address it other than what Dennis mentioned.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
That would mean you could not install an under cabinet light on a wood cabinet without spacers.
kwired
Electron manager
- Location
- NE Nebraska
There is a separation requirement for low density celluose fiberboard unless the luminaire is marked for the condition but that would not apply to lay ins unless there is an old ceiling with low density celluose fiberboard located above the dropped ceiling.
mjf
Senior Member
drop ceiling grid
drop ceiling grid
not electrically based, but I remember being told (or overhearing) that the grid should never be closer than 4" to the ceiling joist or "finished" ceiling. I believe this had to do with being able to get the tiles and fixtures in place. Don't think it had anything to do with any electrical or building codes, but not sure.
drop ceiling grid
not electrically based, but I remember being told (or overhearing) that the grid should never be closer than 4" to the ceiling joist or "finished" ceiling. I believe this had to do with being able to get the tiles and fixtures in place. Don't think it had anything to do with any electrical or building codes, but not sure.
MarkyMarkNC
Senior Member
- Location
- Raleigh NC
I've stuffed more 2x4's than I can remember right underneath duct work with no room to spare.
Tell the tin bangers you need 5 inches and they leave you 3 inches
Tell the tin bangers you need 5 inches and they leave you 3 inches
- Location
- Massachusetts
Yeah, and having to enter the cable into the end of the fixture is a real joy.
- Status