“…Due to the power demand and rated currents flowing in the lines and circuits, the FAS power supply voltage is 24 V, unlike other security systems also operated in such facilities, e.g., closed-circuit TV (CCTV), access control system (ACS) or the intrusion detection system (IDS) [50,51]. Such a solution enables individual FASs to be supplied after isolating power from the power grid, the so-called primary power [49,50]. This allows the FAS to function without drawing power from the battery bank, the capacities of which are determined in the form of developing a so-called energy balance, i.e., electricity demand, taking into account alarm and detection currents for all FAS elements and devices [58,59].…”