Made in Japan
Manufacturer: NOHMI BOSAI
Model: FDK Series

Features of FDK Series

• Small monitoring current of 45 µA
• 2-wire system
• Alarm response lamp (LED)
• Simple mounting
• Very easy maintenance
• Very low profile
• Conventional type

Description of FDK Series

• The FDK series photoelectric smoke detectors detect combustion products (smoke) generated by a fire, and transmit an alarm signal to the fire alarm control panel. The photoelectric smoke detector can detect a fire in an earlier stage than a heat detector. Generally, this detector is installed in the spaces such as basements, ordinary floors, corridors, staircases, elevator shafts.

OPERATING PRINCIPLE AND FUNCTION

• The photoelectric smoke detector is composed of a light source, light sensing element, light shielding element and detecting chamber.
• The light source (a light-emitting diode) emits light at intervals of about 3.5 seconds, which does not reach the light sensing element (photo diode) under normal conditions because of the light shielding mold.
• If smoke enters the detecting chamber, the light from the light source is scattered by smoke particles and reaches the light sensing element.
• The light reaching the light sensing element varies with smoke density and if it exceeds the predetermined level, the detector operates and automatically holds its operation.
• The detector then transmits the alarm signal to the fire alarm panel and the response lamp of the detector turns on.

Specification

Wiring Diagram