Basic connection information – Hochiki IFD-E User Manual

Page 9

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Hochiki Europe (UK) Ltd



Fig 7

Block Diagram of the Detector Signal Processing

If the detector has interpreted the optical signals as a fire then it produces the required output responses.
This will be in the form of supply current changes and the illumination of the red fire LED. The fire relay
will also change state if required.

The detector is constantly checking itself to ensure it is performing correctly. If a fault occurs the detector
supply current will reduce, the fault relay will de-energise and the green supply LED will no longer
illuminate constantly.

Basic Connection Information

Fig 8

Basic 2 Wire Connection Diagram

The simplest method of connecting the flame detector is in a 2-wire configuration as shown above. With
a 24Vdc supply the current (i) drawn by a detector/detectors can be monitored to determine the detector
status. The DIL switches within the detector can be set to produce different current values (i) to suit
control systems.