uninterrupted power supply
Facilities for ensuring continued power in the case of a blackout in the normal supply.
Uninterrupted power supply refers to a structure's capacity to provide its users with electrical power in case of a blackout or local power outage. It generally means that an independent power generator is installed, or that sufficient power for normal usage is stored in batteries or other fuel cells.
The capacity concerns supplying users when the normal electrical supply fails. An independent generator or stored-energy provision can support that purpose, rather than requiring every installation to use the same source.
The presence of ordinary electrical wiring does not establish this backup capacity. The definition concerns continued supply during an outage and does not prescribe a particular switching time or the equipment arrangement of a specific commercial UPS product.