All wiring used for life safety and fire alarm systems of highrise buildings shall be installed in approved metal raceways. No other conductors shall be installed in the same raceway or enclosure with the life safety conductors.
Exception: High rise listed and approved "integrated" systems when installed at the same time as the life safety systems.
A. Approved schedule forty (40) PVC may be permitted to be used underground where covered by a minimum of four inch nominal concrete. This applies to interior building slabs only.
B. When conduit is installed underground on the exterior of the building, it shall be at least thirty (30) inches below grade. (Prior code §§ 9.28.1280, 15.19.1901)