The NFPA 99 Health Care Facilities Code sets out the basic rules for how various systems and equipment in healthcare facilities should be installed, perform, and function. It aims to keep patients, staff, and the public safe from electrical failures, fires, and other dangers.

In NFPA 99, emergency generators are considered part of what’s called an essential electrical system (EES). This system includes backup power sources, all the connected distribution systems, and extra equipment. Its job is to make sure that power keeps flowing to specific areas and functions in a healthcare facility, even if the regular power sources fail. It’s also designed to minimize any disruptions in the facility’s internal wiring systems.