Power supply unit designed to provide fire protection devices with auxiliary power. Metal casing with keyed lock, in 1 mm thick DC01 sheet steel and with IP30 protection rating. Total available current: 2A. Maximum recommended capacity for battery housing (with connection in series) 2 x 12 V / 18 Ah. Power supply voltage: 230 VAC. Nominal output voltage 22 V - 27.6 VDC (standard operation, no battery). The power supply unit is equipped with 2 outputs with volt-free relays (1A @ 30 VDC or 50 VAC) for the signals required by EN54-4. Equipped with an internal sensor for measuring the temperature of the batteries and a tamper device on the front door. Cable glands supplied. Dimensions (WxHxD): 390 x 406 x 96 mm. Approved to EN 54-4, EN12101-10.