NEC 400.7/400.8, round ?

[TSeibel]

I have read through several threads dealing with flexible power cords and suspended ceilings. In the AV business the method of mounting a projector from the ceiling, routing the flexible power cord through the mounting pipe, and attaching the plug to a receptacle mounted above the ceiling is VERY common for non plenum situations. As shown below:

Here is an example of how receptacles for projectors are sometimes installed

And the receptacle -NICE

The common rule simply is: no outlets above plenum ceilings, but non plenum is OK.

This seems to be unresolved. Some of my colleagues suggest 400.7(8) allows us power a projector in this fashion. It has been done a thousand times over without the rebuttal of an inspector. Others (like Pierre) does not agree. I also liked Roger's point from another thread:

'Since "Pendants" are specifically permitted to be connected by flexible cord, 400.7(A)(1), you say it is legal to run this cord strapped to a structural ceiling, through a door way, then strap it to a wall for say 10 feet, then through a hole in the wall, then strap it up a wall to a suspended ceiling, then through a hole in this suspended ceiling to a receptacle located above the ceiling, is this correct?'

....this made me laugh.

The AV industry has produced several UL listed solutions to allow integrators to use this method in plenum situations. For example, this product from Chief Manufacturing:
http://www.chiefmfg.com/productdetail.aspx?AccessoryID=208

This box is mounted above the ceiling inline with the pipe that the projector mounts to. The installer routes the cabling through the mounting pipe and into the box where it plugs into an outlet mounted on the inside of the box. This allows for the flex plug to be connected to an outlet above the ceiling without being exposed to the plenum space. This box is UL listed.

So: If 400.7(8) does not allow me to power a projector from above a lay-in tile ceiling then this box by Chief also violates 400.8(5) and (6); but UL approved this box and the function it serves.

Thoughts?

 

[raider1]

The product in question is listed to UL50 which is Titled "Enclosures for Electrical Equipment, Non-Environmental Considerations". So UL evaluated the product as a enclosure for electrical equipment.

I still think this product is a violation of 400.8(5) because the cord will still be concealed and located above a suspended ceiling.

Chris

 

[iwire]

I agree with Chris.

Just because an item is UL listed does not make it correct for every application. An extension cord is UL listed, I still can not run it through the ceiling.

A simple solution is to install power outlet in the tile facing down.

Some of these mounts actually provide a support for doing so.

 

[TSeibel]

I'm aware of mounting options. I am unaware of UL ratings (obviously). Does this really mean that thousands of installations are in violation AND inspectors are overlooking these installations? Powering equipment above a drop ceiling is very common. If this is a violation, why is it so common?

This biggest issue we have is providing the flexibilty of mounting a projector within a given area leavang flexability for lighting and ductwork, while directing the electrician to install an outlet flush in the ceiling.

Sometimes we run into this:

 

[roger]

Does this really mean that thousands of installations are in violation AND inspectors are overlooking these installations?

Yes it does.

Roger

 

[raider1]

Yes it does.

Roger

I agree.

Just because it is done quite often does not mean it is not a violation.

Alot of these installations are done after a building has been finaled out so they are not even being inspected. And there are inspectors that are not aware that this is a violation.

Chris

 

[iwire]

Does this really mean that thousands of installations are in violation

Yes without a doubt in my mind

AND inspectors are overlooking these installations?

I doubt that inspectors see many of these installations. In my experience 99% of the time this equipment goes in long after construction has been completed and electricians are not pulling permits to install a couple of duplex outlets for the AV guy.

Powering equipment above a drop ceiling is very common. If this is a violation, why is it so common?

Yes it is and see above.

This biggest issue we have is providing the flexibilty of mounting a projector within a given area leavang flexability for lighting and ductwork, while directing the electrician to install an outlet flush in the ceiling.

Yeah construction can be a pain but that is the nature of it.

 

[TSeibel]

http://www.nigelbdesign.com/RackFrame System PDF Files/2008/Plenum Equipment Box New Size.pdf

Here is another MFG, claiming to solve the 400.8 rule.

Tell me your thoughts on this.....

 

[raider1]

http://www.nigelbdesign.com/RackFrame System PDF Files/2008/Plenum Equipment Box New Size.pdf

Here is another MFG, claiming to solve the 400.8 rule.

Tell me your thoughts on this.....

Well first off it appears that they are referencing the 1999 NEC due to the fact that they use the section number 400-8. The dash numbering of NEC code sections was changed to a dot system in the 2002 NEC, so in the 2002 this section is now 400.8.

NEC ARTICLE 400-8 and 400-8(5)......page 219 of the code states: That Flexible Cords and Cables are not permitted to be run through Walls,
Structural ceilings, Suspended Ceilings, or Dropped Ceilings. In addition the revision to 400-8 specifically prohibits these cords being used without
being properly enclosed. Regulations also prohibits the Installation of open Power Outlets in these spaces.

The section that I bolded in the manufactures literature is wrong. The wording in all the subsequential editions of the NEC after the 99 do not have any wording that permits a cord to be installed within a suspended ceiling if it is "properly enclosed".

It appears that the manufacture of this product wants to read the code as they want it to read and not as it is actually written.

Here is how the 2008 NEC section 400.8(5) reads:

"(5) Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings "

Chris

 

[cowboyjwc]

I'm aware of mounting options. I am unaware of UL ratings (obviously). Does this really mean that thousands of installations are in violation AND inspectors are overlooking these installations? Powering equipment above a drop ceiling is very common. If this is a violation, why is it so common?

My guess it there are thousands of installations without permits.