outlet above drop ceiling

[Smart $]

Fair enough. By the letter of the law/code-yes, intent-no. The NEC really stinks at times.

The power supply is for an antenna system. That makes it a Chapter 8 installation.

C90.3 Code Arrangement. This Code...
...
Chapter 8 covers communications systems and is not subject
to the requirements of Chapters 1 through 7 except where
the requirements are specifically referenced in Chapter 8.

So unless 400.7/400.8 is specifically referenced in Chapter 8, those requirements end at the receptacle... IMO...

 

[jumper]

The power supply is for an antenna system. That makes it a Chapter 8 installation.



So unless 400.7/400.8 is specifically referenced in Chapter 8, those requirements end at the receptacle... IMO...

I gotta think about this. Something bothers me about this.

 

[Smart $]

I gotta think about this. Something bothers me about this.

While 400.7/400.8 may not apply, here's one that will...

800.3 Other Articles.
...
(B) Equipment in Other Space Used for Environmental
Air. Section 300.22(C) shall apply.

(C) Other Space Used for Environmental Air. This section
applies to space used for environmental air-handling
purposes other than ducts and plenums as specified in
300.22(A) and (B). It does not include habitable rooms or
areas of buildings, the prime purpose of which is not air
handling.
FPN: The space over a hung ceiling used for environmental
air-handling purposes is an example of the type of other
space to which this section applies.
Exception: This section shall not apply to the joist or stud
spaces of dwelling units where the wiring passes through
such spaces perpendicular to the long dimension of such
spaces.
(1) Wiring Methods. The wiring methods for such other
space shall be limited to totally enclosed, nonventilated,
insulated busway having no provisions for plug-in connections,
Type MI cable, Type MC cable without an overall
nonmetallic covering, Type AC cable, or other factoryassembled
multiconductor control or power cable that is
specifically listed for the use, or listed prefabricated cable
assemblies of metallic manufactured wiring systems without
nonmetallic sheath. Other types of cables, conductors,
and raceways shall be permitted to be installed in electrical
metallic tubing, flexible metallic tubing, intermediate metal
conduit, rigid metal conduit without an overall nonmetallic
covering, flexible metal conduit, or, where accessible, surface
metal raceway or metal wireway with metal covers or
solid bottom metal cable tray with solid metal covers.
(2) Equipment. Electrical equipment with a metal enclosure,
or with a nonmetallic enclosure listed for the use and
having adequate fire-resistant and low-smoke-producing
characteristics, and associated wiring material suitable for
the ambient temperature shall be permitted to be installed
in such other space unless prohibited elsewhere in this
Code.
Exception: Integral fan systems shall be permitted where
specifically identified for such use.

 

[Smart $]

While 400.7/400.8 may not apply, here's one that will...

I should have wrote "may" rather than "will".

 

[iwire]

IMO there is nothing in 800 that applies to the line voltage supply to the equipment.

 

[kwired]

It is clearly still above the ceiling within a box or not.

IMO a violation.

The second floor is above the first floor suspended ceiling...

It might be worded poorly but I don't think the intent is to mean that if it is installed within some other enclosure that is is any longer within the space of the dropped ceiling. We can install conductors or cables not allowed in a ceiling used for environmental air in a metal raceway and they are not considered in the environmental airspace any longer. But I could be wrong - it has happened before.

In the case of a wall wart above the ceiling we cloud the issue even more. Is the load side of this power supply even covered by art 400? Are they a tye of cord listed in 400.4? They are part of an assembly - not going to say they are always listed assemblies.

Does it have to be a hoffman encloser or can it just be a screw cover pullbox?

Yes, Hoffman paid lots of money to get their products required by code

 

[Dennis Alwon]

Can I run UF in a trench?

I knew what section you were referring to but non plenum grade phone wire is not allowed in a plenum. If it is in conduit it is not in the plenum and that is why it is allowed. I see the cord as the same situation. Yes the cord is above the ceiling but protected in a box. Do I think it is safe- yes do I think an AHJ could call you on it -Yes, as I have mentioned. But IMO, it meets what I think the intent is but I did say run it by the AHJ. Technically you are correct as the code is written.


It would be a good proposal for the 2017 NEC for someone to write up.

 

[Dennis Alwon]

The difference is the use of the word plenum and above the ceiling. Could you run NM cable in a conduit in a commercial space about a ceiling? The same scenario applies.

 

[iwire]

It might be worded poorly but I don't think the intent is to mean that if it is installed within some other enclosure that is is any longer within the space of the dropped ceiling.

I am not so sure, the basic theme with cords is to keep them exposed and in site.

We can install conductors or cables not allowed in a ceiling used for environmental air in a metal raceway and they are not considered in the environmental airspace any longer.

I agree.

In the case of a wall wart above the ceiling we cloud the issue even more. Is the load side of this power supply even covered by art 400? Are they a tye of cord listed in 400.4? They are part of an assembly - not going to say they are always listed assemblies.

In the case of a wallwart I think the installation would be fine.

It was my understanding is in this case the power supply has a cord but I could be wrong about that.

 

[Smart $]

IMO there is nothing in 800 that applies to the line voltage supply to the equipment.

Not directly, if you are referring to after the receptacle. The point is that Chapter 8 applies to the line-voltage cord, if any, as it is part of the equipment.

800.1 Scope. This article covers communications circuits
and equipment.