Receptacles Above Suspended Ceilings
- Thread starter dlhoule
- Start date
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winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
IMHO there needs to be a discussion of just what 'above' means in this context.
I know that by the simplest understanding, one location is 'above' another if you can draw a line from the center of the earth through the lower location and then though the upper location. Pretty darn simple.
Yet if we use this meaning of 'above', then under 400.8(6) you couldn't use flexible cords on the second floor of a structure if there were a suspended ceiling on the first floor. Clearly electricians, customers, and inspectors have a shared understanding that 'above' stops somewhere...probably right at the finished floor of the next floor up
In the case of a very large room/building (I am imagining an aircraft hanger), with a smaller room inside it. The smaller room has a suspended ceiling. By a reasonable understanding, where does 'above' this ceiling end.
It seems to me that any space that can be easily seen or accessed from the open floor (outside of the smaller room) would be considered by most everyone to be outside of the space restricted by 400.8(6). Build a sturdy floor over the small room (say for materials storage), and by common usage it would definitely be outside of the space restricted by 400.8(6).
But as Charlie notes, the code says what it says, and it clearly says 'above' with no explicit definition of above. Better start rewiring all those office buildings
-Jon
I know that by the simplest understanding, one location is 'above' another if you can draw a line from the center of the earth through the lower location and then though the upper location. Pretty darn simple.
Yet if we use this meaning of 'above', then under 400.8(6) you couldn't use flexible cords on the second floor of a structure if there were a suspended ceiling on the first floor. Clearly electricians, customers, and inspectors have a shared understanding that 'above' stops somewhere...probably right at the finished floor of the next floor up
In the case of a very large room/building (I am imagining an aircraft hanger), with a smaller room inside it. The smaller room has a suspended ceiling. By a reasonable understanding, where does 'above' this ceiling end.
It seems to me that any space that can be easily seen or accessed from the open floor (outside of the smaller room) would be considered by most everyone to be outside of the space restricted by 400.8(6). Build a sturdy floor over the small room (say for materials storage), and by common usage it would definitely be outside of the space restricted by 400.8(6).
But as Charlie notes, the code says what it says, and it clearly says 'above' with no explicit definition of above. Better start rewiring all those office buildings
-Jon
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
chevyx92 said:
If you think about it, most all of the uses not permitted for cords have to do with them being visible for their entire length. I think that is a big reason.
For example, you can't have them in a raceway (generally speaking). We know raceways are safe, so why can't you put a cord in it? I think it is a visibility issue, so that you can see if the cord has degraded.
- Location
- Simi Valley, CA
Chris,
They don't install those systems here. We just built a new mall and every one of them was taken out and hard wired.
They don't want the cords conceled for the same reasons many cities and now the NEC won't allow NMC above a suspended ceiling.
They don't install those systems here. We just built a new mall and every one of them was taken out and hard wired.
They don't want the cords conceled for the same reasons many cities and now the NEC won't allow NMC above a suspended ceiling.
chevyx92
Senior Member
- Location
- VA BCH, VA
ryan_618 said:
I'm talking about them being in a drop ceiling, all you have to do is pop a tile out if you want to see the cord. I don't understand why you would think it has to be visible the entire length? Whats gonna go wrong??? If the ceiling wasn't plenum then I would see a problem with the cord in an accessible ceiling. Look at the cords on microwaves above a range, they are plugged into an outlet in a cabinet above. The cord isn't visible unless you open the cabinet doors, right? Same goes for disposal cords. I know thats a bit different but just bringing up that you can't see those cords either.
ryan_618
Senior Member
- Location
- Salt Lake City, Utah
Again, I'm just stating opinions that I have been told. The fact of the matter is, the cord won't be visible if it is above a suspended ceiling. Is that how it got into the code...I have no idea. Is that why its in the code...I have no idea. That is just a theory that I have heard.
dlhoule wanted to know "why its in the code", and I was submitting submitting that I have heard.
dlhoule wanted to know "why its in the code", and I was submitting submitting that I have heard.
- Location
- Massachusetts
chevyx92 said:
Yes that is true, but in my opinion the CMP wants the cords visible to all occupants, not just those who open tiles.
Go back to Ryan's post, if you read the prohibited uses of flexible cord the general prohibition is against concealing them.
When rubber cords are left stationary for long periods of time they tend to rot. The insulation drys out and starts to crack, then if it is flexed the insulation falls off.
I have seen a number of cords do this.
Given this insulation breakdown issue and the fact that there are plenty of other NEC compliant wiring methods, MC, NM, AC, EMT, etc there is no reason for the NEC to allow cords above ceilings.
That is true, but is much more likely the cabinet door gets opened more than a ceiling tile and the microwave itself is likely to break down long before the cord rots.
A light fixture is usually a much more 'permanent' installation than a Microwave or a GD.
chevyx92
Senior Member
- Location
- VA BCH, VA
IMO a cord plugged in an outlet below ceiling is at much greater risk of damage. A cord plugged into an outlet above a ceiling would be out of the way.iwire said:
iwire said:
No different than if the cord was tucked back behind a cabinet or desk or 20+ years.
iwire said:
I wasn't suggesting it be a fixed wiring method, just be able to have a cord and plug connected outlet above ceiling and it be legal. Which I know it's not and yet we always install outlets above ceiling per drawings. But we are providing the opportunity for a code violation by doing this and it's ok by code.
This is probably true but just speculation.iwire said:
- Location
- Simi Valley, CA
I think part of the idea is not to use flexible cord at all. Uses not permitted: As a substitute for the fixed wiring of a structure.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Suoppose I have a suspended ceiling without any tile in it??? I did a restaurant years back in an old mill that wanted the beams exposed and they hung a ceiling as a design--- the dropped grid was only in part of the restaurant and abruptly ended-- not at a wall.
I really don't expect an answer to this but it shows how difficult it would be for the code to address every issue.
I really don't expect an answer to this but it shows how difficult it would be for the code to address every issue.
- Location
- Massachusetts
Well chevyx92 I don't know what to say.
The fact is, it is against code to run cords above a suspended ceiling.
You asked for some reasons why and some knowledge people gave you some thoughts.
You can reject each idea but that does not provide you with the answer as to why it is against the NEC.
Flexible cords are not even in chapter 3 with all the other wiring methods, it is clear to me that cords are only interned to be used when necessary.
The fact is, it is against code to run cords above a suspended ceiling.
You asked for some reasons why and some knowledge people gave you some thoughts.
You can reject each idea but that does not provide you with the answer as to why it is against the NEC.
Flexible cords are not even in chapter 3 with all the other wiring methods, it is clear to me that cords are only interned to be used when necessary.
Last edited:
chevyx92
Senior Member
- Location
- VA BCH, VA
I do understand what your saying. I was just looking for a good reason besides "Its not allowed by code" as to why a cord can't be plugged in an outlet above a suspended ceiling.iwire said:
Pierre C Belarge
Senior Member
- Location
- Westchester County, New York
chevyx92 said:
the good reason is that the NEC does not permit it. I myself hear alot of complaints in the field about this installation restriction...my answer is to write a proposal if you are not satisfied and wait for a response.
OSHA take on it
OSHA take on it
1910.305(g)(1)(iii)
Unless specifically permitted in paragraph (g)(1)(i) of this section, flexible cords and cables may not be used:
1910.305(g)(1)(iii)(A)
As a substitute for the fixed wiring of a structure;
1910.305(g)(1)(iii)(B)
Where run through holes in walls, ceilings, or floors;
1910.305(g)(1)(iii)(C)
Where run through doorways, windows, or similar openings;
1910.305(g)(1)(iii)(D)
Where attached to building surfaces; or
1910.305(g)(1)(iii)(E)
Where concealed behind building walls, ceilings, or floors.
OSHA take on it
1910.305(g)(1)(iii)
Unless specifically permitted in paragraph (g)(1)(i) of this section, flexible cords and cables may not be used:
1910.305(g)(1)(iii)(A)
As a substitute for the fixed wiring of a structure;
1910.305(g)(1)(iii)(B)
Where run through holes in walls, ceilings, or floors;
1910.305(g)(1)(iii)(C)
Where run through doorways, windows, or similar openings;
1910.305(g)(1)(iii)(D)
Where attached to building surfaces; or
1910.305(g)(1)(iii)(E)
Where concealed behind building walls, ceilings, or floors.
Dennis Alwon said:
Dennis, I would say you don't have a "ceiling" but you have a decrotative structure. I did a large furnature store a few years ago and they installed a grid system to support the lighting and did not intend to put in pads. the inspector at first said it was a ceiling but after a little disscussion he agreed it was nothing more than a decorative structure. Without pads there is no seperation of air space. just my thoughts here
acdcmontana
Member
There exists certain unusual circumstances which do not have viable alternatives for example and such as cook lines in commercial kitchens; they typically utilize computer monitors overhead at the ends of each cooking island. The apart from hoods the remaining tops of the cooking islands are usually quite hot during cooking operations and can readily exceed the melting point of typical monitor power cords. I may have seen a framed-out grid section of sheet rock with a clock receptacle centered for just such a purpose, but I can?t remember.
smithacetech
Member
- Location
- Utah
Im gonna throw a bone out here.
400.8 Unless specifically permited in 400.7, flexible cords and cables shall not be used for the following:..........
400.7 Uses permited
(A) Uses. Flexible cords & cables shall be used only for the following:......
(2) Wiring of luminaires (fixtures)
Now the way I see it, if an item being installed is on the list of 400.7 permitted uses, such as a light fixture, then 400.8 does not apply. So the fixture can be wired with a cord located above a dropped ceiling.
Anyone wanna bite on this one?
400.8 Unless specifically permited in 400.7, flexible cords and cables shall not be used for the following:..........
400.7 Uses permited
(A) Uses. Flexible cords & cables shall be used only for the following:......
(2) Wiring of luminaires (fixtures)
Now the way I see it, if an item being installed is on the list of 400.7 permitted uses, such as a light fixture, then 400.8 does not apply. So the fixture can be wired with a cord located above a dropped ceiling.
Anyone wanna bite on this one?
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