Journeyman Electrician Exam (NEC)Wiring Methods and MaterialsMedium
An electrician is installing a new 20-amp, 120-volt circuit for a dedicated refrigerator outlet. The circuit consists of 12 AWG THHN conductors run in a 1/2-inch EMT conduit. The conduit passes through a fire-rated wall. What is the NEC requirement for sealing the penetration of the conduit through the fire-rated wall?
- ANo sealing is required for metal conduits passing through fire-rated walls.
- BWrap the conduit with fire-rated tape, then fill with standard caulk.
- CFill the opening with non-combustible material only if the opening is larger than 1/2 inch.
- DSeal the opening with an approved firestop material to maintain the fire resistance rating of the wall.
Show answer & explanationAnswer & explanation
Correct answer: D. Seal the opening with an approved firestop material to maintain the fire resistance rating of the wall.
NEC 300.21 requires that openings around electrical penetrations through fire-resistant-rated walls, floors, or ceilings be sealed with approved methods to maintain the fire resistance rating of the barrier. This typically involves using firestop materials.
Why the other options are wrong
- A. Incorrect. Sealing is absolutely required for all penetrations through fire-rated assemblies, regardless of conduit material.
- B. Incorrect. Fire-rated tape and standard caulk are generally not sufficient or approved firestop methods for maintaining the fire rating of a wall penetration.
- C. Incorrect. The requirement is not dependent on the size of the opening, and 'non-combustible material only' may not be sufficient to maintain the fire rating.
Firestop Requirements
Any penetration of a fire-resistant-rated assembly by electrical wiring or equipment must be sealed with an approved firestop system to prevent the spread of fire and smoke.
- NEC 300.21 directly addresses the protection of openings in fire-rated barriers.
- The firestop material must be 'approved' for the specific application and rating.
- Failure to properly firestop can compromise building safety and violate code.
Memory trick: Seal the hole, save a soul!