Plug in low voltage transformer.

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Hoovs08

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Can a plug in transformer 120vac to 16.5vac be plugged in above a drop ceiling? The 16.5 volts will be feeding a power supply that is also above ceiling?
 
If by "plugged" you mean there will be a flexible cord with a cord cap and you intend to plug it into a standard receptacle outlet, no this is not allowed. NEC article 400.8(5) forbids the use of flexible cords above a suspended ceiling.
 
NEC 2005 400.8 Uses not permitted
Unless specifically permitted in 400.7, flexible cords and cables shall not be used for the following:
(1) As a substitute for the fixed wiring of a structure
(2) Where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors
(3) Where run through doorways, windows, or similar openings
(4) Where attached to building surfaces
Exception to (4): Flexible cords may be attached to building surfaces according to 368.56(B)

(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings
(6) Where installed in raceways, except as otherwise noted in the code.
(7) Where subject to physical damage
 
The transformer plugs directly into the outlet. There are two output terminals on the transformer (16.5vac) that a plenum 2 conductor tie to that go to the power supply. Tranformer is also "captive" to the receptacle.
 
charlie b said:
If by "plugged" you mean there will be a flexible cord with a cord cap and you intend to plug it into a standard receptacle outlet, no this is not allowed. NEC article 400.8(5) forbids the use of flexible cords above a suspended ceiling.
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I have often thought this was one of the safest places to put corded equipment. Wonder what their thinking was on this when they wrote it.
 
JohnJ0906 said:
http://i125.photobucket.com/albums/p66/JohnJ0906/HPIM0455.jpg

http://i125.photobucket.com/albums/p66/JohnJ0906/HPIM0456.jpg

http://i125.photobucket.com/albums/p66/JohnJ0906/HPIM0458.jpg

Here are a few shots of a cord that spent a few years in a ceiling. This is the part that I stripped - this was inside the cord jacket, and still had rotten insulation.
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Nice pics John... I always picture the ceiling grid becoming energized with cords in the ceiling... that would be a nice surprise. :roll:
 
stickboy1375 said:
Nice pics John... I always picture the ceiling grid becoming energized with cords in the ceiling... that would be a nice surprise. :roll:
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I know I have heard people talk about what happens to cords in a ceiling, but when I actually found one, I knew I had to take a few pictures for "illustration" purposes. :wink:
 
plug-in trans

plug-in trans

I think what the original post was about was the use of plug-in transformers with LVT, which is not the same thing as extension cord. Plenum or Riser-rated LVT is commonly run in t-bar ceilings for class 2 circuits. Plug-in transformers have internal fuses, which makes this installation a class 2 circuit.

There is another type of "in-line" LV transformer with a length of 110v lamp cord running to the receptacle and class 2 LV wiring coming out the other side of the transformer housing. Using this in t-bar seems like a code violation since only the secondary side is class 2, and where plenum wiring was required it would not be suitable either.

Is the receptacle above the ceiling tile a code violation itself?
 
ItsHot said:
This is a common violation. Overhead projectors, condensate pumps.. common or not ,it is still a violation.
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I see TV's done like this everywhere... not sure what is so hard about cutting a receptacle into the ceiling tile?
 
We have a situation where there is a security camera hanging from a 2x4 drop ceiling. The security guys ran the low voltage cabling from the security camera above the drop ceiling and ran the cables down into a receptacle that was located inside a wall cabinet. I'm trying to explain to them this still violates the code where flexible cables are not permitted above drop ceilings. They were trying to get away with doing that, but I don't think that is ok..... right?
 
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