Earthquake Switches & Triggers

Earthquake Switches

The CJS earthquake safety switch is designed to sense a vibration by earthquake via its micro-switch, which automatically cuts off an electrical circuit when an earthquake over a certain magnitude occurs. Ideally used in conjunction with our gas shut off valves.


Technical Specifications:

  • setting acceleration: cutting off in horizontal movement between 1.0m/s2and 1.7m/s2 as per 0.3sec to 0.7sec cycle
  • contact rating: 230Vac 7A
  • 1 SPDT relay contact for remote alarm and/or electrical shut off
  • indicator lamp enables after earthquake
  • manual reset
  • operating temperature: -20°C to 70°C
CJS-C117Tmechanical earthquake switch, manual reset, non-adjustableDownload Datasheet

Earthquake Triggers

The earthquake trigger continuously monitors the vertical component of the earth’s acceleration due to seismic forces. It is designed to detect the faster moving P- waves and, when the acceleration exceeds the pre-set level, the output relay changes state until 7 seconds after the quake. Contacts on this relay may be used to initiate any desired action. The unit has an event counter mounted on the lid to record the total number of operations, including instrument test operations.

Technical Specifications:

  • vertical sensitivity: 0.012, 0.025, 0.05, 0.1, 0.2G selectable
  • frequency response: flat from 0.3Hz..10Hz (+/-3dB). 10dB down at 30Hz
  • operation time: 10m/s, relay is de-energised 7 seconds after event
  • power supply: 230Vac with NiCAD battery backup
  • contact rating: 230Vac 10A
  • test button to simulate 0.2G earthquake
MK5 EQ TRIGelectronic earthquake triggerDownload Datasheet