Raised Floor Outlets

[steve66]

Are receptacles permitted under a raised floor? (Note that per the definition in Article 100, this is NOT a concealed location).

Are power strips permitted to pass through a hole in a raised floor and plug into a receptacle under the raised floor?

Finally, is an extension cord allowed to be used under a raised floor, or to pass through a hole in the raised floor?

This is an occupied office space, not an information technology room.

Steve

 

[laclede]

Re: Raised Floor Outlets

Depends on if the raised floor space is a plenum space or not. If it is not an air handling space then yes, extension cords and power strips are allowed. If it is an air handling space, then same rules as above the ceiling apply, and smoke detection is required also!

 

[steve66]

Re: Raised Floor Outlets

Oh, I forgot...not an air handling or plenum space.

Steve

 

[ron]

Re: Raised Floor Outlets

If 645 will not apply then you go to 400.8, which prohibits the cord from being installed in many areas such as through floors and as a replacement of fixed wiring.
No prohibition for receptacles, it is the cord that can't go there, so in effect the receptacle can't either.

 

[steve66]

Re: Raised Floor Outlets

Thanks for the replies.

400.8(2) : Flexible cords and cables shall not be used where run through holes in walls, structural ceilings, suspended ceilings, dropped ceilings, or floors.

400.8(5): Where concealed by walls, floors, or ceilings or located above suspended or dropped ceilings.

I?m not sure if ?floors? in the above includes ?raised floors?. I would say no, because they separate out suspended and dropped ceilings, but not floors and raised floors. Also, 400.8(%) refers to ?concealed?, but the definition of ?concealed? says items below removable floor panels are not concealed.

Anyone agree or disagree?

 

[ron]

Re: Raised Floor Outlets

I don't think (5) applies.
I was referring to (2).
I think suspended and dropped ceilings are the same. IMHO (2) applies to raised floor tiles.

[ June 04, 2004, 09:52 AM: Message edited by: ron ]

 

[joe tedesco]

Re: Raised Floor Outlets

See 300.22(D)

 

[rbalex]

Re: Raised Floor Outlets

In my opinion, I think what is being described is a violation of 400.8(1) for powerstrips

While there is no direct violation with the receptacle itself, the wiring method used is a substitute for bringing the outlet up to a wall mount or floor monument. Powerstrips are neither appliances nor utilization equipment

For other uses ?specifically? permitted by 400.7, such as 400.7(A)(3), (A)(6), and (A)(8), I believe current wording of the Code would permit simple extension cords installed per 400.7(B). Many of us work in offices where desk and work surface portals permit cords to pass through. So it's not the passing through holes itself that?s dangerous but the potential of mechanical damage with peoples feet shuffling around and other traffic.

Having said this, extending the concept of 400.7(A)(3), (A)(6), and (A)(8) to powerstrips might be reasonable for an AHJ to approve. I would want to see substantial mechanical and abrasion protection at the penetration. I would require that for 400.7(A)(3), (A)(6), and (A)(8) installations too.

 

[ron]

Re: Raised Floor Outlets

Joe,
He inferred that he did not want to use the leniencies permitted by 645.

 

[charlie b]

Re: Raised Floor Outlets

Originally posted by steve66: I?m not sure if ?floors? in the above includes ?raised floors??. but the definition of ?concealed? says items below removable floor panels are not concealed. Anyone agree or disagree?

I disagree. The Article 100 definition of ?Concealed? (2002 version) includes the clarification, ?Wires in concealed raceways are considered concealed, even though they may become accessible by withdrawing them.? I could not find a definition that says ?items below removable floor panels are not concealed.? May I ask where you found that clarification?

Here?s my take on the issue. If you install conductors inside a conduit, and if you have the proper OCPD, you can have confidence that they are safe from most hazards that might cause damage. A flexible cord is not so safe. I think that is why the code forbids concealing flexible cord. If it were to suffer damage from any cause, the damage would not be in plain sight, and therefore might go undetected. Running an extension cord from cubicle to cubicle leaves the cord essentially in plain sight, so that is not a problem. Running individual conductors along the base of a cubicle wall is not a problem either, since the base is a UL listed raceway. But running an extension cord under a raised floor allows any possible damage to remain hidden for a long time. After all, even if you can remove the floor panels and inspect the cord from time to time, no one will actually do that.

 

[steve66]

Re: Raised Floor Outlets

Thanks again for all the replies.

Charlie b: I got the idea below a raised floor is not concealed from the handbook (I know the handbook isn't binding code, but I assume the people writing it have a better idea of the intent behind the requirements than I do).

Handbook commentary for definition of "Concealed":

Raceways and cables supported or located within hollow frames or permanently closed in by the finish of buildings are considered concealed. Open-type work - such as raceways and cables in exposed areas; in unfinished basements; in accessible underfoor areas; or behind, above, or below panels designed to allow access and that may be removed without damage to the building structure or finish - is not considered concealed. [See the definition of exposed (as applied to wiring methods)].

Steve

 

[ron]

Re: Raised Floor Outlets

Steve,
By the looks of Holts last newsletter, it appears he disagrees with me, and suggests 400.8(2) does not include raised floors.
Other thoughts?

 

[jimwalker]

Re: Raised Floor Outlets

I too read it and having hard time seeing this cord as being ok under a floor.Just how often would anyone ever see it?

 

[steve66]

Re: Raised Floor Outlets

Ron: Thanks a million for the tip on the Mike Holt newsletter. I know his opinions are not 100% guaranteed, but I think they do carry some weight.

jimwalker: My preference would be to set the outlets right under the access holes. Thus, only a few inches would be below the raised floor, and it would be easily visible with a flashlight.

I really don't like the idea of using extension cords (which was suggested by a client). I would rather use a power strip and keep the cord as short as possible.

Steve