The IS Sonos sounder beacon has been approved for use in potentially explosive atmospheres for Group I (Mining) & Group II (Above Ground) applications and incorporates a high Ingress Protected IP66 enclosure. The sounder beacon unit incorporates a two stage alarm option and has a total of 32 selectable tones, selectable via a dip switch on the PCB and produces up to 105dB at 1 Meter. A specially designed time saver base enables quick and easy installation of this unit with no extra cabling to be made to the head of the unit. Connections are made to the base during the initial wiring phase which results in a faster more reliable installation. The sounder head simply twists & clicks into the pre-fixed base on commissioning avoiding any additional wiring & connections. Further details can be found on the installation sheet’ This unit must be used in conjunction with an approved Zener Barrier or Galvanic Isolator. The characteristics should not exceed Uo: 28v, Io: 93mA, Po: 660mW, Ci: 0, Li 0. The minimum value of Uo should not drop below 23.6v and the minimum value of Io should not drop below 50mA.