A protective wiring assembly includes a raceway having a top portion, a bottom portion that is opposite the top portion, and a self-closing portion intermediate the top and bottom portions. The bottom portion has a bottom locking rib and interfaces a support on which the assembly can be disposed. The self-closing portion has a top locking rib and a top guide rib. The top locking rib is engageable to the bottom locking rib. A cover interfaces the top portion of the raceway. The cover has a pair of retention legs and a load bearing rib that transmits force from the top portion to the support.