Journeyman Electrician Exam (NEC)Wiring Methods and MaterialsEasy
A residential electrician is installing a new 20-amp, 120-volt branch circuit in a dwelling unit. The circuit will be run through a bored hole in a wood stud. What is the minimum distance required from the nearest edge of the stud to the bored hole for the cable, assuming no steel plate protection is used?
- A1 1/4 inches
- B1/2 inch
- C1 inch
- D3/4 inch
Show answer & explanationAnswer & explanation
Correct answer: A. 1 1/4 inches
According to NEC 300.4(A)(1), where cables or raceways are installed in bored holes in wood members, the hole must be located at least 1 1/4 inches from the nearest edge of the wood member. If this distance cannot be maintained, steel plates or sleeves of at least 1/16 inch thick must be installed.
Why the other options are wrong
- B. Incorrect. This distance is too small and does not provide adequate protection.
- C. Incorrect. This distance is too small and does not provide adequate protection.
- D. Incorrect. This distance is too small and does not provide adequate protection.
Bored Hole Cable Protection (Wood)
NEC requirement for protecting cables from nails or screws when routed through bored holes in wood framing members.
- Prevents damage to conductors from fasteners.
- Requires specific spacing or steel plate protection.
- Applies to studs, joists, rafters, and similar wood members.
Memory trick: Wood Wires Need Wide Clearance.