Which wiring method is permitted to protect NM cable when passing through a floor?

Which wiring method is permitted to protect NM cable when passing through a floor?

• A. RTRC-XW
• B. EMT
• C. PVC
• D. RMC

Answer: (A)

Passing NM cable through a floor requires mechanical protection so it won’t be damaged by nails, screws, or floor movement. The code allows NM to run through a listed raceway designed for through-floor installations, which provides a continuous, protective channel through the floor. RTRC-XW is a rigid conduit type listed specifically for protecting NM cable in floor penetrations and for use in locations that may be exposed to moisture. This makes it the appropriate, permitted method for this situation. Other conduit types exist, but they are not listed here for through-floor protection of NM in the same way, so they aren’t the preferred choice in this context.

Passing NM cable through a floor requires mechanical protection so it won’t be damaged by nails, screws, or floor movement. The code allows NM to run through a listed raceway designed for through-floor installations, which provides a continuous, protective channel through the floor. RTRC-XW is a rigid conduit type listed specifically for protecting NM cable in floor penetrations and for use in locations that may be exposed to moisture. This makes it the appropriate, permitted method for this situation. Other conduit types exist, but they are not listed here for through-floor protection of NM in the same way, so they aren’t the preferred choice in this context.