Reserve Supply 2 : (Hcf-PipSys) Where provided, that portion of the source equipment that automatically supplies the system in the event of failure of the primary and secondary operating supply
NFPA 99 Standard for Health Care Facilities, 2002 ed. https://law.resource.org/pub/us/cfr/ibr/004/nfpa.9 9.2005.pdf, (Std: Hlth Care Fcilty - Amer) {242 NFC}