Emergency generators are required in many applications where facility operations are to continue to perform even upon a failure of the electric grid. The best resources for quantifying the emergency generation classifications, capacities, installation, maintenance, and operational testing requirements are the building codes and federal regulations. These codes include NFPA, IBC, NEC, and in institutional occupancies like hospitals, the federal regulations headed by the Center for Medicare and Medicaid Services, CMS.
The driving code is the International Building Code (IBC). The IBC identifies the systems that are required to be served with a backup power source. Backup power is divided into two categories: emergency and standby.