The power supplies, used in an evacuation center should be robust. There are also high demands on the reliability of these system components. Each part of the installation depends on this system component.
Therefore, there is formulated within the product standard the requirement that the applied power supplies must comply with the requirements as stated in the standard EN54-4.
This product standard describes the minimum requirements for this power supplies.
The power supply in the fire safety world simultaneously fulfill the function as emergency power system. The emergency power is almost always a battery pack that is connected to the power supply. The standard refers to a primary power supply that is connected to the mains and a secondary power supply that should be a battery system.
There is sometimes a confusion about the time a secondary supply should deliver its ability. This used to be 12 hours. The new standard refers to functionality at full capacity for 24 hours.
That latter is in full force. This is a European requirement and this outweighs a national requirement