The STX2405 is an EN54-4 approved power supply, ideal for use in fire, smoke, and ventilation control systems. Its regulated 27.6V DC output provides up to 5 A continuous to the load while also supplying up to 850 mA for charging standby batteries up to 17Ah.
The output features electronic short-circuit protection under both mains and standby battery operation. Maximum battery life is ensured through continuous active monitoring and a two-stage charger (bulk and temperature-compensated float) that adapts to battery condition.
When fully charged, the STX2405 operates in Eco power-saving mode, checking and topping up the battery every 24 hours without wasting energy, extending the operational life of the batteries. Deep discharge protection prevents premature battery failure during extended standby operation.
Key Features:
Certified by UL to EN54-4:1997 +A1:2002 +A2:2006
Up to 5 A current at 27.6V DC nominal output
Supports 7 or 17Ah batteries
Electronic overload protection shuts down output until faults are cleared
Battery monitor detects missing, low, short-circuited, or reverse-connected batteries
Charging circuit activates only when battery is correctly connected and above 14 V
No loss of output during automatic battery connection on mains failure
Deep discharge protection disconnects battery at 21 V
Diagnostic LED (orange) for internal checks
Fault LED (yellow) flashes for output, battery, charger, or mains faults
Mains LED (green) shows mains presence and checks at start-up
Optional RS232 serial interface for fault reporting and diagnostics
Compatible with batteries up to 2 × 7Ah
'C' Box Power Supply: 275 × 330 × 80 mm with hinged lid
Dimensions
400mm W x 420mm H x 80mm D