Based on the 2023 NEC.
Question: Conductors installed under or encased in not less than _____ of concrete are considered to be outside of a building.
See answer below.
Answer: 2 in.
Explanation: Section 230.6 gives the conditions where conductors shall be considered outside of a building or other structure. Section 230.6(1) lists "Where installed under not less than 2 in. of concrete beneath a building or other structure" and Sec. 230.6(2) lists "Where installed within a building or other structure in a raceway that is encased in concrete or brick not less than 2 in. thick" as conditions.
Lupacchino is a senior design engineer with Gaylor Electric, Inc. in Noblesville, Ind. and serves as an alternate on NEC Code-Making Panel No. 3. He is currently licensed in more than 80 jurisdictions. He can be reached at [email protected]