The last nail and the turn of the screw

Section 300-4(a)(1) points out that where subject to physical damage conductors shall be adequately protected. Cables and raceways installed through bored holes in joists, rafters or wood members, require that those holes will be bored so that the edge of the hole is not less than 1- in. from the nearest edge of the wood member. Where this distance cannot be maintained, the cable or raceway must be

Joseph A. Tedesco

Oct. 1, 2001

Section 300-4(a)(1) points out that “where subject to physical damage” conductors shall be adequately protected. Cables and raceways installed through “bored holes” in joists, rafters or wood members, require that those holes will be bored so that the edge of the hole is not less than 1-¼ in. from the nearest edge of the wood member. Where this distance cannot be maintained, the cable or raceway must be protected from penetration by screws or nails by a steel “kick” plate or bushing, at least 1/16-in. thick. This protection must be of appropriate length and width (meaning wider than the wood member) and be installed to cover the area of the wiring. Steel plates are not required to protect rigid metal conduit, intermediate metal conduit, rigid nonmetallic conduit or electrical metallic tubing. By the looks of this installation, the last nail or screw will be the one that leaves a message that will be answered in the future. Murphy's Law says that that nail or screw may cause a fire or overcurrent condition. “Overcurrent” is defined in Article 100.