Location of Sealing Fitting in Class I, Division 1 Location

A sealing fitting shall be installed within _____ of either side of the boundary where a conduit leaves a Class I, Division 1 location.

a) 5 ft
b) 6 ft
c) 8 ft
d) 10 ft

See answer and applicable Code reference

The correct answer is: d) 10 ft

Article 501 outlines the requirements for electrical and electronic equipment and wiring in Class I, Division 1 and 2 locations. As noted in a portion of 501.15(A)(4), "The sealing fitting shall be permitted on either side of the boundary of such location within 10 ft of the boundary and shall be designed and installed so as to minimize the amount of gas or vapor within the Division 1 portion of the conduit from being communicated to the conduit beyond the seal."