24VDC Electric Fire Bell The bell remains the most commonly used alarm for fire evacuation system, for wall applications, indoors. They are designed to be used in 24 volt DC systems. Wiring The system designer must make sure that the total current drawn by the devices on the loop does not exceed the current capability of the panel supply, and that the last device on the circuit is operated within its rated voltage. When calculating the voltage available to the last device, it is necessary to consider the voltage drop due to the resistance of the wire. The thicker the wire, the smaller the voltage drops. Wire resistance tables can be obtained from electrical handbooks. Specifications Voltage ranges: 20vdc to 28vdc (Nonp olarity) Power and current consumption: 1W, 38ma@24vdc(maximum) Number of standard: EN54-3 Sound levelï¼?80dBï¼?Aï¼?@1M (minimum) Service Use: Fire alarm, general signaling, burglar alarm Environment type: TypeA(indoor) Input terminal Wire Gauge: 0.28 mm 2 to 1.5 mm 2 Operating Temp.: -10â?? to +55â?? Operating Humidity Range: 10% to 93% Relative Humidity ( Non-condensing) Material of cover:Aluminum Dimension: 150mmÃ?50mmï¼?D*H) (Without bracket) Weight: Net Weight 342g, Gross Weight 395g