fire alarm system >> control logic - italy

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Description

The IR flame detector model RIV-601/F is an electronic optical fire detecting device which responds immediately to the thermal infrared radiation emitted by fire and is tuned to the flickering frequency of the flame to ignore sun and lamp light. It is enclosed in a cast aluminum watertight case with IP66 grade protection, which allows to withstand dusty environment and rain. An IP66 explosion-proof enclosure is provided for the RIV-601/FA model. Nominal 24VDC input power is required, with wide span allowed, and two different outputs are provided: one heavy changeover relay contact, and one NPN transistor open collector. Both outputs go into alarm state after a pre-set time delay, but they come back to the stand-by state as soon as the fire stops.

 The delay time is normally set to 5 seconds, but can be set in the range from 1 to 10 seconds .A protection against the 24VDC power voltage inversion is provided. Sensitivity is 2-3% of the distance, that means a 10 cm flame at 5 m distance, or a 20 cm flame at 10 m .The field of view is a 90°cone, but beyond 90° the detector can see with reduced sensitivity, and can also see behind obstacles due to reflections. A small dust build-up over the detector window does not decrease too much the detector ability, since thermal infrared radiation is little attenuated by dust, much less than light is. Therefore a frequent window cleaning is not required. Also smoke does not blind the detector, which is operating well with fires in heavy smoke.