These requirements cover metal underfloor duct systems designed for use as raceways for the installation of wires and cables in accordance with the National Electrical Code (NEC)@ NFPA 70. These requirements do not cover rigid or flexible conduit surface raceways or other products of a similar nature that are covered by individual requirements separate from these requirements. General compliance of underfloor raceway systems in accordance with the construction and performance requirements in this standard shall be determined by a study of an actual installation of the system or a completely representative sample installation.