# receptacles above grid ceilings



## jeelec (Jan 30, 2014)

is it permissable to install receptacles above ceilings? NEC400.8 says no.


----------



## sbrn33 (Mar 15, 2007)

So why ask?


----------



## Big John (May 23, 2010)

Sure it is. You just can't legally plug anything into them.


----------



## Pete m. (Nov 19, 2011)

Big John said:


> Sure it is. You just can't legally plug anything into them.


That's almost 100% true. Some class 2 or 3 transformers (the ones that have the molded plugs) could be permitted.

Pete


----------



## Big John (May 23, 2010)

Pete m. said:


> That's almost 100% true. Some class 2 or 3 transformers (the ones that have the molded plugs) could be permitted.
> 
> Pete


 Like these guys?


----------



## ponyboy (Nov 18, 2012)

jeelec said:


> is it permissable to install receptacles above ceilings? NEC400.8 says no.


That's not what 400.8 says though. It's the cord


----------



## Pete m. (Nov 19, 2011)

Big John said:


> Like these guys?


Yea. 

The OP quoted the prohibition for "cord" above the ceiling. A lot of class 2 and 3 wiring methods are permitted above a ceiling.

Pete


----------



## cultch (Aug 2, 2011)

We did it all the time for the security guys. Never failed.


----------



## Mshow1323 (Jun 9, 2012)

cultch said:


> We did it all the time for the security guys. Never failed.


We can all agree that Art. 400 deals with flexible cords, and it prohibits the original posters question. If we look at Appendix A, Flexible Cords and Cable are covered by UL 62 ie Art. 400. Now look toward the top of the list of Appendix A and you'll see that Cord Sets and Power-Supply Cords are covered by UL 817, thus not Art. 400. 

"Flexible Cords" and "Cord Sets" are two entirely different animals. This is the reason why you've "never failed."
Cord sets are manufactured power cords (which happen to be CL2 or CL3), much like a tv or computer cord. Generally extension cords (UL 62) and custom build cords are considered "flexible," and pre-made are "Cord Sets" (UL 817). :thumbsup:

EDIT: I also firmly believe, that this will always be classified as a gray area. There is also a reason why you always see projectors with their cords run through the ceiling....because it's ok


----------



## manchestersparky (Mar 25, 2007)

Mshow1323 said:


> We can all agree that Art. 400 deals with flexible cords, and it prohibits the original posters question. If we look at Appendix A, Flexible Cords and Cable are covered by UL 62 ie Art. 400. Now look toward the top of the list of Appendix A and you'll see that Cord Sets and Power-Supply Cords are covered by UL 817, thus not Art. 400.
> 
> "Flexible Cords" and "Cord Sets" are two entirely different animals. This is the reason why you've "never failed."
> Cord sets are manufactured power cords (which happen to be CL2 or CL3), much like a tv or computer cord. Generally extension cords (UL 62) and custom build cords are considered "flexible," and pre-made are "Cord Sets" (UL 817). :thumbsup:
> ...



I see someone has been watching Mike Holt on you tube


----------



## Big John (May 23, 2010)

I was gonna argue that I think this rule is out-dated because I think most modern cords resist dry-rotting pretty well when compared to old rubber cords. But I wonder if the logic behind this isn't the same as the prohibition for Romex, because of smoke loading during a fire?


----------



## ponyboy (Nov 18, 2012)

Big John said:


> I was gonna argue that I think this rule is out-dated because I think most modern probably cords resist dry-rotting pretty well when compared to old rubber cords. But I wonder if the logic behind this isn't the same as the prohibition for Romex, because of smoke loading during a fire?


On another somewhat related note. When is the last time you've seen the space above a drop ceiling used as a plenum? Maybe it's common in warmer climates but I've never seen it or heard of it being done in this area


----------



## Awg-Dawg (Jan 23, 2007)

ponyboy said:


> When is the last time you've seen the space above a drop ceiling used as a plenum?


 
The majority of ceilings I have seen were plenum.


----------



## Big John (May 23, 2010)

I built a couple highrises down south where the ceilings were plenum. My commercial experience in New England is too limited to really speak on it, but none of the ones I can recall were plenum.


----------



## KGN742003 (Apr 23, 2012)

Anyone ever have to feed a cord connected condensate pump above a suspended ceiling? How did you do it?


----------



## wendon (Sep 27, 2010)

I've installed recepts on top of a beer cave so the sign cord wouldn't have to be plugged in on the front.


----------



## Big John (May 23, 2010)

KGN742003 said:


> Anyone ever have to feed a cord connected condensate pump above a suspended ceiling? How did you do it?


I've put in a lot of drop-ceiling receptacles. If some other trade comes behind me and just happens to plug in projectors and televisions and condensate pumps, that's not my problem. :whistling2:


----------



## ablyss (Feb 8, 2014)

This looks like an outdated topic but nevertheless I'll jump in. 
The original question was about receptacles in drop ceilings, not cords. I guess people just assume anything you plug into a receptacle has a cord. Not true. Yes you can install receptacles in drop ceilings and as long as the appliance is in accordance with the code like article 400.8 you have nothing to worry about.


----------



## dspiffy (Nov 25, 2013)

ponyboy said:


> On another somewhat related note. When is the last time you've seen the space above a drop ceiling used as a plenum?


I cant remember having seen it done, in the midwest or the south. Of course it happens sometimes unintentionally when people mess with HVAC.

The elementary school my wife attended in the 80s burned down in the 2000s, I saw the investigation report. Apparently there was "faulty wiring" serving "faulty fluorescent lights" in the plenum space, which arced and ignited the ceilings.


----------



## Deep Cover (Dec 8, 2012)

90% of the commercial spaces we work in have plenum rated ceilings.


----------



## ponyboy (Nov 18, 2012)

Deep Cover said:


> 90% of the commercial spaces we work in have plenum rated ceilings.


Crazy. You're not too far from me and it's unheard of around here


----------



## Deep Cover (Dec 8, 2012)

One thing I've always wondered is that why plenum ceilings were such a big deal. Is it because that space is concealed?

The majority of the manufacturing facilities we work in are basically plenum rated buildings.


----------



## Bkessler (Feb 14, 2007)

Deep Cover said:


> One thing I've always wondered is that why plenum ceilings were such a big deal. Is it because that space is concealed? The majority of the manufacturing facilities we work in are basically plenum rated buildings.


Isn't the plenum used for a cold air return?


----------



## ablyss (Feb 8, 2014)

For sake of clarification plenums are spaces that allow airflow. A sealed airtight shaft would not be a plenum.

Some structures will use plenums for the purpose of heating and cooling, as well as wire assemblies.

Wire assemblies are discouraged in plenums because of the history of abandon wires, and the combustion factor of oxygen enriched spaces. 

Plenums include drop ceilings in buildings and residential homes. They may or may not be used as part of the HVAC but should always be treated as such and should not be used as a storage facility for abandoned wires and ducts. The weight of the plenum is not designed for such and creates a risk of injury.


----------



## Big John (May 23, 2010)

ablyss said:


> ...Some structures will use plenums for the purpose of heating and cooling, as well as wire assemblies....Plenums include drop ceilings in buildings and residential homes. They may or may not be used as part of the HVAC but should always be treated as such and should not be used as a storage facility for abandoned wires and ducts....


 Following the NEC definition, this isn't accurate. A plenum is not just any open space in which air may flow, it is a space specifically dedicated to carrying environmental air:


> *Plenum*. A compartment or chamber to which one or more air ducts are connected and that forms part of the air distribution system.


A space above a drop-ceiling is not automatically a plenum unless it is an integral part of the HVAC system.


----------



## Edrick (Jun 6, 2010)

So if the return and delivery are ducted to vents in the drop ceiling it should not be a plenum space correct?


----------



## ablyss (Feb 8, 2014)

Big John said:


> Following the NEC definition, this isn't accurate. A plenum is not just any open space in which air may flow, it is a space specifically dedicated to carrying environmental air:A space above a drop-ceiling is not automatically a plenum unless it is an integral part of the HVAC system.


Actually, to be a little more precise plenums are ANY non-habitable area that allow airflow. Even so, to make your head spin even more :boxing: :turned:, a habitable area could be a plenum if that was part of the design.

*Article 300.22(C):nerd:*


----------



## Big John (May 23, 2010)

Edrick said:


> So if the return and delivery are ducted to vents in the drop ceiling it should not be a plenum space correct?


 That's my understanding.


----------



## ponyboy (Nov 18, 2012)

Edrick said:


> So if the return and delivery are ducted to vents in the drop ceiling it should not be a plenum space correct?


That's how I see it


----------



## ponyboy (Nov 18, 2012)

Big John said:


> That's my understanding.


Quit stealing my thunder. I needed that one.


----------



## Big John (May 23, 2010)

ponyboy said:


> Quit stealing my thunder. I needed that one.


 I can't come up with any way of saying you can have your thunder back that doesn't sound really gay. So I'm just gonna quietly leave the thread....


----------



## Going_Commando (Oct 1, 2011)

Mshow1323 said:


> We can all agree that Art. 400 deals with flexible cords, and it prohibits the original posters question. If we look at Appendix A, Flexible Cords and Cable are covered by UL 62 ie Art. 400. Now look toward the top of the list of Appendix A and you'll see that Cord Sets and Power-Supply Cords are covered by UL 817, thus not Art. 400.
> 
> "Flexible Cords" and "Cord Sets" are two entirely different animals. This is the reason why you've "never failed."
> Cord sets are manufactured power cords (which happen to be CL2 or CL3), much like a tv or computer cord. Generally extension cords (UL 62) and custom build cords are considered "flexible," and pre-made are "Cord Sets" (UL 817). :thumbsup:
> ...


----------



## LGLS (Nov 10, 2007)

dspiffy said:


> The elementary school my wife attended in the 80s burned down in the 2000s, I saw the investigation report. Apparently there was "faulty wiring" serving "faulty fluorescent lights" in the plenum space, which arced and ignited the ceilings.


 Unless a forensic investigator was there and witnessed it with a bus load of nuns, while it was happening, I don't believe it. All fires are deemed electrical when no other cause can be found. The finger gets pointed to the electrical thing that looks the worst.


----------



## Pete m. (Nov 19, 2011)

IslandGuy said:


> Unless a forensic investigator was there and witnessed it with a bus load of nuns, while it was happening, I don't believe it. All fires are deemed electrical when no other cause can be found. The finger gets pointed to the electrical thing that looks the worst.


I hate to contradict you but ALL fires are electrically caused.

Even lightning is electrical....:whistling2:

Pete


----------



## Edrick (Jun 6, 2010)

Pete m. said:


> I hate to contradict you but ALL fires are electrically caused. Even lightning is electrical....:whistling2: Pete


So a match is electric? Cigarettes?


----------



## LGLS (Nov 10, 2007)

Pete m. said:


> I hate to contradict you but ALL fires are electrically caused.
> 
> Even lightning is electrical....:whistling2:
> 
> Pete


 Spontanious combustion? Arson? School fire = teachers cigarettes!


----------



## Monkey Ninja (Dec 11, 2013)

We put them in ceilings in commercial all the time for above ceiling mounted hot water heaters as a disconnectig means never a problem the problem lies when you run the cord through the ceiling.


----------



## Pete m. (Nov 19, 2011)

Edrick said:


> So a match is electric? Cigarettes?


Take it easy Bro... I was trying to make a bit of a joke. 

It does seem when the cause of a fire is unknown it is magically related to electric.

Pete


----------



## Magoo5150 (Mar 1, 2007)

manchestersparky said:


> I see someone has been watching Mike Holt on you tube


 
I do not watch the You Tube videos but just got through with his Changes in the 2014 DVD class. Do you have any argument in what he is saying is right or wrong when it comes to "factory" cordsets in a suspended ceiling?
I tend to agree with Mike Holt but am open to other opinions. His panel seems to always be a reputable bunch of guys and a few of them sit on one or more CMP's.


----------



## hornetd (Oct 30, 2014)

IslandGuy said:


> Unless a forensic investigator was there and witnessed it with a bus load of nuns, while it was happening, I don't believe it. All fires are deemed electrical when no other cause can be found. The finger gets pointed to the electrical thing that looks the worst.


:no:

That is only true were trained fire investigators are not employed. Were the reporting fire official is properly trained in the application of NFPA 902: Fire Reporting Field Incident Guide the incident report will usually be an accurate reflection of the actual cause of the fire. :thumbsup: 

-- 
Tom

Well we aren't no thin blue heroes. Yet we aren't no blackguards to.
We're just working men and women most remarkable like you.


----------



## Cl906um (Jul 21, 2012)

Monkey Ninja said:


> We put them in ceilings in commercial all the time for above ceiling mounted hot water heaters as a disconnectig means never a problem the problem lies when you run the cord through the ceiling.


I agree 100 percent. This code was invented after the bar remodel fires. The insurance company thought the bars burned down due to cords from window signs/ pool table lights fed 50 feet away passing through the drop ceiling and plugging into a three way tinsel cord. When actually the bar owner threw a match to her for a remodel.


----------



## chewy (May 9, 2010)

We'd be screwed over here... big commercial fitouts we just put 3 prong outlets in the ceiling zip tied to catenary wires and just plug the fluorescent fittings in, so easy to work on them as you just pull the plug.


----------



## bullmike (Jun 13, 2011)

Receptacles are allowed above a ceiling ,but NOT flexible cord according to 400.8 (5). If you had a listed "appliance" i.e. a condensation pump for a air handler as many have done that must be legal.


----------

