Service Conductors

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nizak

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I am looking at installing Sch40 Rigid PVC Conduit from the meter base, under a garage cement floor, and then up the opposite exterior garage wall and into the service panel. It will be traveling approx. 4' vertically up the stud wall cavity after it emerges from the garage footing and into the panel.(owner doesn't want pvc running up the outside wall because it's going to be a patio/ hot tub area).Would this be up to the AHJ's discretion as to whether or not a disconnecting means would be required at the meter base? I believe the wording is "nearest the point of entrance" for the service disconnect location. Would a 4' length of RMC up the wall be a better way to go as far as protecting the conductors? Thanks.
 
The conduit within the concrete is considered outside of the building which has a unlimited length. IMO the conduit run straight up into the bottom of the panel is OK.
 
RMC is not a requirement and unless your area has amended the NEC then IMO your are okay. The only question may be whether or not the panel is allowed in the wall between the garage and the home. I am getting at fire rating here- done it many time and never got called on it but...
 
Panel will be on exterior garage wall, no dwelling space behind it just a stamped concrete patio and hot tub.
 
Two things I'd do; go deeper on run of conductors under Slab (more than NEC) and increase the outside wall to 6" inches... Good Luck
 
The exterior wall is going to be 6". What would the benefit be for going deeper under the slab? Thanks.
 
eHunter said:
To help prevent damage during the slab pour and future damage.
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That, and I could see a case being made that in the floor is not considered outside the building.

Now, we do have 230.6 to help us.

NEC said:
230.6 Conductors Considered Outside the Building.
Conductors shall be considered outside of a building or
other structure under any of the following conditions:
(1) Where installed under not less than 50 mm (2 in.) of
concrete beneath a building or other structure
(2) Where installed within a building or other structure in a
raceway that is encased in concrete or brick not less
than 50 mm (2 in.) thick
(3) Where installed in any vault that meets the construction
requirements of Article 450, Part III
(4) Where installed in conduit and under not less than
450 mm (18 in.) of earth beneath a building or other
structure
(5) Where installed in overhead service masts on the outside
surface of the building traveling through the eave
of that building to meet the requirements of 230.24
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I personally would be comfortable with the top of the PVC 2" below the top of the slab, but one could easily interpret that to mean a 2" layer of concrete poured above the PVC, with the top of that in the same plane as the bottom of the final slab, to meet sub-section (1).

Or at least, 2" above and below to meet sub-section (2).
 
He could keep pouring concrete around that raceway all the way up the wall and to the panel. Surrounding the raceway with 2" of concrete is good enough regardless of whether it is underground or above for whatever length you want to go.
 
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