General – Hochiki IFD-E User Manual

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Hochiki Europe (UK) Ltd




The flame detector is designed for use where open flaming fires may be expected. It responds to the light
emitted from flames during combustion. The detector discriminates between flames and other light
sources by responding only to particular optical wavelengths and flame flicker frequencies. This enables
the detector to avoided false alarms due to such factors as flicking sunlight.

Electrical Considerations

The flame detector can be connected in many different electrical configurations depending on the
application. The detector requires a 24Vdc (14Vmin. to 30Vmax.) supply to operate. The detector can be
connected as a two-wire loop powered device increasing its supply current to signal that a flame has
been detected. See Fig 8. The supply connections to the detector are polarity sensitive.

Also available are volt free contacts from two internal relays RL1 (Fire) and RL2 (Fault or pre-alarm).
Using the relay contacts connected in a four-wire configuration the detector status can be signalled back
to control equipment. See Fig 9.

Removing the detector front cover provides accesses the detector terminals and configuration DIL switch.
See Fig.4.

Alarm Response Modes

The detector is normally configured to latch into an alarm state when a flame is detected. The supply to
the detector has to be broken in order to reset the detector.

The configuration DIL switch within the detector can be set to place the detector into a non-latching mode.
The detector can then also produce proportional analogue current alarm signals, in other words, 8-28mA
or 4-20mA. In non-latching mode the detector only produces an alarm signal when a flame is in view
resetting itself to normal when the flame has gone.