receptacle location question
- Thread starter dcv
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- Status
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: receptacle location question
I think I?ve seen this discussion before. What I recall is that 400.8(2) prohibits a flexible cord from being installed above a suspended ceiling. If you can?t plug in a cord, then why would you install a receptacle?
I think I?ve seen this discussion before. What I recall is that 400.8(2) prohibits a flexible cord from being installed above a suspended ceiling. If you can?t plug in a cord, then why would you install a receptacle?
Re: receptacle location question
Good answer
and I understand , but the fact still remains its ok for the outlet to be there ,what if I plugged in a device that had no cord something with the prongs mounted directly on the device like maybe a low voltage transformer.
and yes this is a similar, kind of, repeat subject in which I have not seen answered yet.
Craig
Good answer
and I understand , but the fact still remains its ok for the outlet to be there ,what if I plugged in a device that had no cord something with the prongs mounted directly on the device like maybe a low voltage transformer.
and yes this is a similar, kind of, repeat subject in which I have not seen answered yet.
Craig
- Location
- Massachusetts
Re: receptacle location question
The NEC calls that space "Other Space Used for Environmental Air" If it is that kind of space I agree that the outlet, being non-metallic, would have to be rated for use in "air handling spaces".
But you said it is "not an return air plenum" if the space is not used for air handling there would be no special listing requirements for this receptacle.
Now you made me think of the plug in transformers and the equipment that they power.
Are they listed for use in air handling spaces?
First if the the space above a suspended ceiling is used as the return it is not a plenum.
The NEC calls that space "Other Space Used for Environmental Air" If it is that kind of space I agree that the outlet, being non-metallic, would have to be rated for use in "air handling spaces".But you said it is "not an return air plenum" if the space is not used for air handling there would be no special listing requirements for this receptacle.
Now you made me think of the plug in transformers and the equipment that they power.
Are they listed for use in air handling spaces?
Re: receptacle location question
n. pl. ple?nums or ple?na (pln, pln
A condition, space, or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere.
Bob
isn't everything above a lay in tile ceiling that is not metal required to be plenum rated,even if it is or is not used for air return.Inculding the receptacle
n. pl. ple?nums or ple?na (pln, pln
A condition, space, or enclosure in which air or other gas is at a pressure greater than that of the outside atmosphere.
Bob
isn't everything above a lay in tile ceiling that is not metal required to be plenum rated,even if it is or is not used for air return.Inculding the receptacle
- Location
- Massachusetts
Re: receptacle location question
If the space above the ceiling is not used as air handling space it just "space" no different from an attic.
Bob
Why would any equipment need to have special listing for use above a ceiling that is not used as an air handling space?Originally posted by dcv:
.
Bob
isn't everything above a lay in tile ceiling that is not metal required to be plenum rated,even if it is or is not used for air return.Inculding the receptacle
If the space above the ceiling is not used as air handling space it just "space"
no different from an attic.Bob
- Location
- Massachusetts
Re: receptacle location question
When applying the NEC we must use the NEC definitions.
I would point out we can not use the everyday definition of plenum, the NEC has provided a definitions of "plenum" and "Other Space Used for Environmental Air"
When applying the NEC we must use the NEC definitions.
- Location
- Lockport, IL
- Occupation
- Semi-Retired Electrical Engineer
Re: receptacle location question
Let?s go back to basics. When we talk of plenum-rated, what is the problem that we are trying to solve, or what is the hazard that we are trying to prevent? An answer to that question should answer the question of when to buy plenum-rated equipment.
The problem with an electrical component being installed within a plenum is that the air moving past the component will soon find its way into a room in which people are working. If that component is prone to release smoke or nasty gases when it gets hot, then the air moving towards the people space will be poisoned (or at least, unpleasant). Components that are constructed to be plenum-rated will not have materials that release vast great amounts of smoke or nasty gases.
Let?s go back to basics. When we talk of plenum-rated, what is the problem that we are trying to solve, or what is the hazard that we are trying to prevent? An answer to that question should answer the question of when to buy plenum-rated equipment.
The problem with an electrical component being installed within a plenum is that the air moving past the component will soon find its way into a room in which people are working. If that component is prone to release smoke or nasty gases when it gets hot, then the air moving towards the people space will be poisoned (or at least, unpleasant). Components that are constructed to be plenum-rated will not have materials that release vast great amounts of smoke or nasty gases.
Re: receptacle location question
However,I never had an inspector ask me if a space above the ceiling was being used as an air return but, I have had them point out cables pulled which were not plenum rated located in a space above a ceiling which was not being used as a air plenum.Guess I could have called him on it.
Since I hardly ever deal with plenum cable, It's
easier for me to just buy Plenum rated cable when I do have to deal with it.....To avoid any
problems.
Thanks,
Craig
I guess your right Bob,I have just always treated both spaces the same by using plenum rate cable above a ceiling ,if it were being used as air return or not.
However,I never had an inspector ask me if a space above the ceiling was being used as an air return but, I have had them point out cables pulled which were not plenum rated located in a space above a ceiling which was not being used as a air plenum.Guess I could have called him on it.
Since I hardly ever deal with plenum cable, It's
easier for me to just buy Plenum rated cable when I do have to deal with it.....To avoid any
problems.
Thanks,
Craig
Re: receptacle location question
First, I agree that if the space is not used for air handling, then there is no special reqirement for electrical wiring or devices that would be diferent than say, an attic.
Second, let me throw another curve in to the "plenum" definition issue. As iwire said, if we're discussing NEC requirments, we need to use NEC definitions (where they differ from "everyday" definitions). But, the International Mechanical Code (or the Uniform Mechanical Code as applicable) also regulates what can or can't be in air handling spaces (including wiring) as well, and when we're looking at IMC requirements, we have to use IMC definitions. I believe that according to the IMC definition, the space above a ceiling that is used for air handling is a plenum Just food for thought.
First, I agree that if the space is not used for air handling, then there is no special reqirement for electrical wiring or devices that would be diferent than say, an attic.
Second, let me throw another curve in to the "plenum" definition issue. As iwire said, if we're discussing NEC requirments, we need to use NEC definitions (where they differ from "everyday" definitions). But, the International Mechanical Code (or the Uniform Mechanical Code as applicable) also regulates what can or can't be in air handling spaces (including wiring) as well, and when we're looking at IMC requirements, we have to use IMC definitions. I believe that according to the IMC definition, the space above a ceiling that is used for air handling is a plenum
Just food for thought.- Status