The STX2402-x is an EN54-4:1997 +A1 +A2 approved power supply ideal for use in Fire and Smoke and ventilation control Systems. Its regulated 27.6V dc output will supply up to 2 Amps continuous into the load, in addition to providing up to 700 mA for charging the standby batteries up to 18 Ah. The power supply output features electronic short circuit protection under both mains and standby battery operation. Maximum battery life is assured through continuous active battery monitoring and the use of a two stage charger, comprising bulk and temperature compensated final float phase depending upon battery condition. Once fully charged the product operates in Eco power saving mode, whereby the batteries are charged for 4 hours in every 24 hour period while still being continuously monitored. This reduces wasted energy in charging already fully charged batteries and extends their working life. Deep discharge protection prevents premature battery failure when operating from standby for extended periods. Two sets of volt free solid state relay fault output signal (i) loss of mains and (ii) battery fault, charger fault and loss of output. In addition there is an optional plug in serial interface that can provide diagnostic and fault reporting information to supervisory systems.