The last nail and the turn of the screw

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- in. from the nearest edge of the wood member. Where this distance cannot be maintained, the cable or raceway must be

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.

About the Author

Joseph A. Tedesco

Voice your opinion!

To join the conversation, and become an exclusive member of EC&M, create an account today!

Sponsored Recommendations

How to Calculate Labor Costs

Most important to accurately estimating labor costs is knowing the approximate hours required for project completion. Learn how to calculate electrical labor cost.

8 Types of Electrical Conduit and Their Uses

Electrical conduit is a tube or raceway used to house and protect electrical wires within a building or structure. From data centers to underground subways to ports and bridges...

Champion Strut Catalog

Champion Fiberglass is the most advanced manufacturing facility of fiberglass conduit, fiberglass bridge drain and fiberglass strut systems in the world. Its well-trained and ...

Considerations for Direct Burial Conduit

Installation type plays a key role in the type of conduit selected for electrical systems in industrial construction projects. Above ground, below ground, direct buried, encased...