The GDS Defender Gas Alarm

The GDS Defender Gas Alarm features a control unit monitoring up to 16 sensors on a single 3 core cable network, combining high specification with significant cost saving over conventional gas alarm systems.

Standard sensors for use in commercial and light industrial applications such as laboratories, workshops, boiler plant rooms etc are available for monitoring toxic, flammable, oxygen or refrigerant gases. Each sensor incorporates a status LED, alarm sounder and relay. Sensor types may be mixed and up to 16 per zone, or up to 64 when used with an additional auxiliary power pack. Alternatively sensors may be used separately without a control unit providing they are powered by a 24volt DC supply (plug in jack).

The control unit provides four zones, all accepting up to 16 sensors. Each gas sensor continuously monitors the atmosphere for any hazardous conditions, on detection of gas the sensor will indicate the gas level status A1, A2, A3 by LED indication and sounder. Information received by the control panel from the sensor is then displayed, indicating the zone, gas type and alarm status. Alarm levels that are exceeded are then able to activate user selectable relays and appropriate control functions.


  • 3 core network for multiple sensors
  • Sensors pre-set and tested
  • Toxic / Flammable / Oxygen / Refrigerant combination
  • 1-16 sensors – 4 zones (Up to 64 sensors)
  • Three alarm levels (timed ON OFF option)
  • Four zone indicators
  • Connect directly to the GDS Combi CANbus system
  • Designed for ease of installation
  • System easily extended
  • Off the shelf system
  • User definable screen text


  • 115 / 230VAC or / and 24VDC
  • Consumption 3 watts
  • Indicators for standby, alarm and fault
  • Internal 85 dB Alarm
  • Four selectable relays S.P.C.O 3A @ 230vAC
  • Alarm Inhibit
  • Self Diagnostic
  • Dimensions L 200mm x H 150mm x D 80mm
  • Weight 920 gms