Outlet in t-bar cieling

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JdoubleU

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In the class rooms that have cieling mounted projectors, the power and low voltage interfaceing is sleaved through the mounting pipe of the projector and plugged into an outlet above the cieling. Is this ok.
 
Not really, see 400.8

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Roger
 
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I replace the tile with a board painted the same color as the ceiling and mount projector on board then I cut in a 2x4 box and mount a receptacle in box that is mounted on the board so face of outlet is below the ceiling and then I plug the projector in to the receptacle..I can then support the board on its own cables so it is not supported by ceiling..I have used the posts like you describe I still just mount a box in the tile with the receptacle access from ceiling side and rock and roll..
 
I always install the receptacle in the ceiling tile using a t-bar bar hanger and a 4 square box and mud ring.

Chris
 
brother said:
I wonder what lead to the reason for this change in the code. Why was it such an ISSUE to have a cord in the drop ceiling?? I still see it happen today for some cameras and some special units in the ceiling.
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Many ceilings are plenums - not many cords are plenum rated. Many cords are not flame spread tested as many premise wiring methods would be. When they burn they are more toxic than other methods. And once it is up there it may not be seen for many years - making it permanent wiring - cords can not be permanent wiring.... Dropped ceilings are an easy path of travel for fire - plenum or not... The NFPA writes our code....

Then there is the 'inch and mile' of it - if you allow one, next thing you know the whole ceiling is full of them and we are out of work, and the whole county is a fire hazard.... All chaos will break loose....:wink: The earth will shift from it moorings and careen toward the sun, etc, etc.
 
e57 said:
Then there is the 'inch and mile' of it - if you allow one, next thing you know the whole ceiling is full of them and we are out of work, and the whole county is a fire hazard.... All chaos will break loose....:wink: The earth will shift from it moorings and careen toward the sun, etc, etc.
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I was wondering why we (the earth) hadnt shifted off the axis yet. ;)
 
How does one address issues of cord-connected lighting fixtures that are mounted flush with a drop-ceiling? I've done work in a restaurant that was full of these. They had basically installed painted plywood in place of some of the 24x48 acoustic tiles and drilled out holes through which 120 V PAR cans were mounted. Since the backs of the fixtures extended above the ceiling, this is where the cord came out and someone strung a couple of receptacles up above the grid in Romex (yes, I know) for just this purpose. It was a very ineffective installation that must have been done at least 20 years ago by a stage lighting installer.

The poor logistics of this situation aside, how does one deal with this type of fixture mounted in a drop ceiling? Powered speakers come to mind as another type of thing that is put in this scenario often.
 
Not to high jack the thread, but I don't like the graphic put up from Holt as it indicates that cords are okay below floors, and that is only compliant in very special situations where the installation complies with Article 645 and the cord is DP rated.
 
There's no exception for a projector in 400.8(2)+(5) but, for 2008, there's a "backdoor" exception for lighting. . I say "back door" because it should be listed as an exception in 300.8 but it's not, it's in 410.62(C)(1)(2)c.

There are, of course, restrictions on when it can be done and when it can't be done.

David
 
brother said:
I wonder what lead to the reason for this change in the code. Why was it such an ISSUE to have a cord in the drop ceiling?? I still see it happen today for some cameras and some special units in the ceiling.
Click to expand...

In addition to what e57 has posted I would like to add, that the rubber outer jacket of flexible cord tends to break down and become brittle and fall off after a relatively short period of time. If you can not see the cord you won't be aware of this happening and won't know to replace the worn out cord.

This problem drives a lot of the restrictions that are part of 400.8.

Chris
 
dnem said:
There's no exception for a projector in 400.8(2)+(5) but, for 2008, there's a "backdoor" exception for lighting. . I say "back door" because it should be listed as an exception in 300.8 but it's not, it's in 410.62(C)(1)(2)c.

There are, of course, restrictions on when it can be done and when it can't be done.

David
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David, Yes the 2008 NEC has changed this section from 410.30 to 410.62 and also added the sentence " having a maximum 152 mm (6 in.) long section of raceway for attachment to an outlet box above a suspended ceiling" to the end of that section.

This section does require that you install a raceway that in no longer than 6" to install the flexible cord through in the suspended ceiling.

Chris
 
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