This standard covers performance requirements for emergency and standby power systems providing an alternate source of electrical power to loads in buildings and facilities in the event that the primary power source fails.
Prior to the 1999 edition, this document assumed that all emergency and standby power sources were rotating equipment. The 1999 edition recognized the use of fuel cells with the grid providing the backup power. This document was reorganized in 2002. The pertinent paragraphs (addressing fuel cells) in the current 2020 edition are 5.1.3 and Annex A.5.1.3. Available at www.nfpa.org