What is an emergency power supply?

     The literature distinguishes between backup power supply and emergency power supply. The role of standby power supply is to enable normal or near-normal operation of a facility (such as a home or business) and the operation of machinery and equipment. The primary role of the emergency power supply, on the other hand, is to protect people in the facility and allow them to evacuate (an example would be emergency lighting). The terms "backup power supply" and "emergency power supply" are colloquially used interchangeably. In this context, the role of standby (emergency) power supply is to provide electricity to electrical consumers so that they can be used during a power outage from the power grid.

      One of the primary sources of emergency power is a generator, which is a device that generates electricity to supply power to a building's electrical system. The genset can be connected to selected appliances/electrical circuits in such a way that it supplies electricity to all consumers (then the users of the house do not see the difference between mains power and from the genset - a very convenient solution).