Conduit under garage slab.

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360Youth

360Youth

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Newport, NC
I'm sure this has been discussed many times, but I still have trouble searching the posts. I need to install parallel conduit runs from a CT cabiniet under the garage to an equipment room (all this is prep work of course, just exterior walls and dirt right now). If I am reading 300.5 correctly the install falls under Col. 3, dwelling driveways. I thought I would fall under the 4" slab but I'm afraid the "no vehicular traffic" wording gets me because of the gargage. Am I reading this correct? Once again, hopefully this is not a subject discussed to death already, if anybody has search tips I would appreciate it.
 
You can go 18" or you can dig a trench deep enough to put it on stands and encase it with a minimum of 2" of concrete.

Or you can call the AHJ and see if scratching a ditch under the slab will suffice. That would be the route I would take first.
 
360Youth said:
I'm sure this has been discussed many times, but I still have trouble searching the posts. I need to install parallel conduit runs from a CT cabiniet under the garage to an equipment room (all this is prep work of course, just exterior walls and dirt right now). If I am reading 300.5 correctly the install falls under Col. 3, dwelling driveways. I thought I would fall under the 4" slab but I'm afraid the "no vehicular traffic" wording gets me because of the gargage. Am I reading this correct? Once again, hopefully this is not a subject discussed to death already, if anybody has search tips I would appreciate it.
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"driveways and outdoor parking areas" isn't the right line if you're talking about the garage itself.

"under a building" is 0 inches

If you were outside with vehicular traffic, 4 inches under a solid concrete slab isn't good enough. . You have to go 12" under 2" of concrete or 18" down if you don't have that finish on top.

But under a building is zero. . Vehicular traffic is not a specification. . Vehicle traffic, it's still zero. . No concrete cover, still zero.

David
 
depth

depth

David, I agree with you on the 0" under a building, however, outside under vehicular traffic, I would say 18" minimum for one&two family and 24" for all other vehicular areas. (My jurisdiction is still 2002).
I wasn't clear on the occupancy, but since he said "equipmet room" I thought commercial.
 
augie47 said:
David, I agree with you on the 0" under a building, however, outside under vehicular traffic, I would say 18" minimum for one&two family and 24" for all other vehicular areas. (My jurisdiction is still 2002).
I wasn't clear on the occupancy, but since he said "equipmet room" I thought commercial.
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Nope. Residence. 9000sqft home with 600a service. The conduit will run directly under the garage floor from exterior ct cabinet to equipment room (disc, ats, hvac, etc). It does not technically fall uner the "outside drive way" but it is ruled out by the "not subject to vehicular traffic." One of those questions you know the answer to but you hope someone will say, "Nah, you're fine, just read...." Oh, well. :grin:
 
Does running under the garage or other part of the building like that count as unfused conductor entering the building?
 
under

under

in that case, i would say 0 under the garage floor, 18" under a resi drive
 
wireman71 said:
Does running under the garage or other part of the building like that count as unfused conductor entering the building?
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Service conductors underneath a building under 2" or more of concrete are considered "outside" the building. Take a look at 230.6(1).

Chris
 
wireman71 said:
Does running under the garage or other part of the building like that count as unfused conductor entering the building?
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If this mega house doesn't have concrete in the garage, for some reason, then yes he could have a problem with 230.70(A)(1)

David
 
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