georgeswe
Senior Member
- Location
- The Republic of Southern California
I would to see if you guys could help me clear this up. We are working in a commercial garage and have receptacles above the tech counters. We opted to run all the conduit feeding these devices underground. The panel room is in an unclassified area of the building and the location of the recepts are in a Class I Div II area. First, we are installing the conduit UG about 12" below slab around the perimeter and more than 24" below finished concrete in any area that will have vehicle traffic. I am looking at 2005 NEC handbook and per per 511.4 (A) the area below the ground of a Class I Div II areas are no longer concidered classified since 2002 NEC. there is an exhibit picture (511.1) which shows how you can install the conduit with no unions or breaks 12" above and below the 18" classified area and not have to install explosion proof fittings. The picture shows conduit passing through the classified area with no Explosion fittings in the same space. This is where I am having the problem, since I have the handbook there is a explanation section here that states :
"It should be noted that general rules of 501.15(A)(4) and (B)(2) on providing seals at classified classified area boundries do apply where raceway installations in a cmmercial garage pass from classified to unclassified locations and conduit fittings, outlet boxes, or both are installed less than 12" from either side of the boundry..."
So now looking at 501.15(A)(4) exception no. 1 states:
"Metal conduit that contains no unions, couplings, boxes or fittings, and passes completely through a class I, Div. I location with no fittings less than 12" beyond each boundry shall not require a conduit seal if the terminating points of the unbroken conduit are in the unslassified locations."
So im looking at it that we are passing through this classified area and we do not have to install seals. However, these conduits are now going from the garage to a panel room in an unclassified area. If we are leaving to a unclassifed area from the garage do we still need to install sealoffs? Even though the exception say I do not need them. Please help me decipher this.
"It should be noted that general rules of 501.15(A)(4) and (B)(2) on providing seals at classified classified area boundries do apply where raceway installations in a cmmercial garage pass from classified to unclassified locations and conduit fittings, outlet boxes, or both are installed less than 12" from either side of the boundry..."
So now looking at 501.15(A)(4) exception no. 1 states:
"Metal conduit that contains no unions, couplings, boxes or fittings, and passes completely through a class I, Div. I location with no fittings less than 12" beyond each boundry shall not require a conduit seal if the terminating points of the unbroken conduit are in the unslassified locations."
So im looking at it that we are passing through this classified area and we do not have to install seals. However, these conduits are now going from the garage to a panel room in an unclassified area. If we are leaving to a unclassifed area from the garage do we still need to install sealoffs? Even though the exception say I do not need them. Please help me decipher this.
