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#84019 - 03/03/03 08:24 PM Above ceiling nightmare!  
HotLine1  Offline

Joined: Apr 2002
Posts: 6,864
Brick, NJ USA
As briefly as I can state this:
2x4 grid ceiling, commercial building, fully sprinklered above and below grid ceiling.
Ceiling cavity is being used for conditioned air (supply) with ducted returns.
There is full access to the area above the grid ceiling, via extensive catwalks.

Installed in the ceiling grid are 2x4 HEPA self powered filter units, UL labeled and listed, with a "factory 5' cord and molded straight prong plug, and a factory speed control pot. Mfg instructions state that a "120 volt receptacle should be installed above or adjacent to the unit for connection"
Based on the layout, duplex 20 amp, 120 volt receptacles in deep 4" sq boxes were installed within reach of the factory cord.

An AHJ states the following:
400-8 prohibits cord/plug connections "above" a drop ceiling, as it is not visable.
"Cord" is not allowed within a plenum ceiling.

My reply:
IF you cannot connect the unit as the mfg intended, how can it be UL listed/Labeled??
The ONLY use for this unit is to filter conditioned air from a "plenum" ceiling, into a "clean" room area.

Comments are appreciated.


[This message has been edited by HotLine1 (edited 03-03-2003).]


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#84020 - 03/03/03 09:39 PM Re: Above ceiling nightmare!  
iwire  Offline
Joined: Jan 2003
Posts: 4,391
North Attleboro, MA USA
Good question we did a job where it was on the print to leave outlets above ceiling for these fancy motorized racks for video projectors and for the projectors themselves, all UL listed equipment with cord and plugs. This passed inspection but it probably was not noticed

Bob Badger
Construction & Maintenance Electrician

#84021 - 03/03/03 09:51 PM Re: Above ceiling nightmare!  
WebSparky  Offline
Joined: Feb 2003
Posts: 138
Cleveland, Ohio

I think he is forgetting 400.7(A)(8)
"...and the appliance is intended or identified for flexable cord connection."

Usually where the code "permits" certain options, the same code does not automatically "take it away". We always need to keep in mind the "spirit of the code" and not just the "letter of the code".


PS. 400.8(2) is refering to "running through holes and alike".
and (5) is where it is concealed in and in the "spirit" of extention cords.

[This message has been edited by WebSparky (edited 03-03-2003).]

[This message has been edited by WebSparky (edited 03-03-2003).]


#84022 - 03/05/03 12:07 AM Re: Above ceiling nightmare!  
HotLine1  Offline

Joined: Apr 2002
Posts: 6,864
Brick, NJ USA
How about a comment from Joe T, or Resqcapt?

We had 100+ of these units installed in one job, and there where "no questions".

The interpertation of 400-8 was "you have to be able to "see" the receptacle & cord from the floor". You cannot "see" thru the ceiling tiles.

Thanks for the input guys!!


#84023 - 03/05/03 01:05 AM Re: Above ceiling nightmare!  
Joe Tedesco  Offline
Joined: Oct 2000
Posts: 2,749
Boston, Massachusetts USA
300.22(C) covers environmental air spaces, see the FPN, and prohibits cord wiring.

(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

(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 factory-assembled 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 and conductors shall 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.


Joe Tedesco, NEC Consultant

#84024 - 03/05/03 11:05 AM Re: Above ceiling nightmare!  
txsparky  Offline
Joined: May 2001
Posts: 552
Magnolia,.Texas U.S.A.
Sounds like the manufacturer needs to read the code book and makee provisions for a hardwired unit or have the cord come out below the ceiling for a ceiling mounted receptacle.(that would be ugly)


#84025 - 03/05/03 02:19 PM Re: Above ceiling nightmare!  
resqcapt19  Offline
Joined: Nov 2000
Posts: 2,148
400.8 was revised for the 2002 code cycle to make it clear that cords are not permitted above ceilings. In the '99 code, the word "concealed" applied to the ceiling space and cords would be permitted above "lay-in tile" ceilings. The word "concealed" was replaced with "located" in the 2002 code.


#84026 - 03/05/03 06:37 PM Re: Above ceiling nightmare!  
HotLine1  Offline

Joined: Apr 2002
Posts: 6,864
Brick, NJ USA
First, and foremost, I thank you all for the comments.

The point that I am trying to make is:
There is no other conceivable use for a HEPA fan/filter of this type other than filtering conditioned air from a plenum into the area under the plenum. (Being a clean room area)

AS the unit comes factory equipped (as an option) with a cord and molded can that be??

My situation was resolved when the operation we installed folded... I bring it up as another contractor had this situation last week...I said "it is OK", another AHJ said "NO", as stated in my original post.

The "job" that I installed was inspected & approved. My opinion was/is that there is access and "visability above the ceiling tiles, via the catwalk and platforms.

Again, thanks for the opinions.

Harold, what do you think????

PS, Yes, I posted this situation at Mike Holt's board, as this site was down.
Joe T: yes, I understand 400-8 and the drop ceiling/plenum ceiling thing. You and I just have a different definition for the same thing, I think.


[This message has been edited by HotLine1 (edited 03-05-2003).]


#84027 - 03/05/03 07:11 PM Re: Above ceiling nightmare!  
Joe Tedesco  Offline
Joined: Oct 2000
Posts: 2,749
Boston, Massachusetts USA
See the specific definition of the term "Plenum" in Article 100, and you will learn that it is not the proper term to use when discussing the (C) pagaraph in 300.22 which calls the space as I described it above.

Joe Tedesco, NEC Consultant

#84028 - 03/05/03 07:21 PM Re: Above ceiling nightmare!  
HotLine1  Offline

Joined: Apr 2002
Posts: 6,864
Brick, NJ USA
"Enviornmental Air Handling Space"
Ya ever hear the one "it's hard to teach an old dog new tricks"

Been callin it a plenum ceiling for a long time; gotta change my ways!
As usual, Thank You


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