110.26(f)(1)

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al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Imagine a concrete wall that was supposed to be three inches thick. The electrical design shows some branch circuit panels surface-mounted onto this wall. All conduits (incoming power and branch circuits) will be entering from the top.

Now imagine that the concrete wall contractor made an error, and began to make the wall nine inches thick. The error was noticed when the wall was about 3 feet high. The rest of the wall, from that point to the ceiling, was built 3 inches thick. As you stand inside the room, and look at the wall, you see the wall coming up from the floor, then it recedes six inches, so that there is essentially a 6 inch lip (upon which you can set your coffee cup).
Correct me if this wall is made of cement blocks, but I'm reading (poured) concrete.

Poured concrete on, what?, a concrete floor?

Who's to say that this 6" flat strip isn't a raised step of the floor.
 

al hildenbrand

Senior Member
Location
Minnesota
Occupation
Electrical Contractor, Electrical Consultant, Electrical Engineer
Back when, I helped with two buildings, side by side, common ownership, that were originally built with only crawl spaces for basements. There was about five feet of clearance between the underside of the first floor joists and the top of the unexcavated earth.

When the owner got each of the buildings, he dug the floor down another four feet, poured a new basement floor and had a little over eight feet of headroom.

The original building footings were left undisturbed, and the earth that was removed started about two feet away from the original footings. This created a "shelf" about 2+ feet wide about 3+ feet up from the new basement floor.

This "shelf" was the old basement floor.

In the case of Charlie B's 9" to 3" poured concrete wall, because of the sturctural capability of the concrete, I think the "shelf" can be given all the weight bearing ability of the other, 3 foot lower floor.
 

charlie b

Moderator
Staff member
Location
Lockport, IL
Occupation
Retired Electrical Engineer
I believe Charlies intent when starting this thread was to point out the deficiencies in the wording of this section.
No, the situation is real, though it did not arise in the way I described. What actually happened is that the concrete contractor started constructing the wall of the electric room about six inches away from where it was supposed to be, making that side of the room 6 inches smaller, and giving that space to the room on the other side of the wall. The error was discovered after some of the wall had been built. Rather than tear down what was built, they just built a wall where it was originally supposed to be. That left an extra thick wall for the bottom few feet, and left the shelf space directly under where the panels are supposed to go.


A coworker described the situation, and asked my opinion. My first thought was that a wall is not "foreign equipment," so it should be OK. But I don't like to answer real-live code questions, without reading the book first. That is when I noticed a possible problem of not having dedicated equipment space from the bottom of the panel all the way to the floor.

Thanks for the replies. I suggested to my co-worker that he check with the AHJ. My own opinion remains that this is acceptable.
 

Smart $

Esteemed Member
Location
Ohio
I think anyone with a lick of sense would call that a jog on a wall not a another floor level.
I was thinking floor level even before I got to Al's post, but my thought was about building a platform, space permitting, at the same height as the ledge (not a 30" deep counter). You could then argue the platform is the floor.

At some point after installation and inspection (CoO), remove said platform... :D
 

tomspark1

Member
Location
Central Florida
Isn't this like having a gutter underneath? I am not near my code book but I think the gutter can protrude no more than 6" beyond the panel front.

'Scuse me...wireway :)
 
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