4-Wire Photoelectric Low-Flow Duct Smoke Detector, 24 VAC/VDC

D4240 photoelectric duct smoke detectors are 4-wire detectors that feature pivoting housings that fit both square and rectangular footprints and mount to round or rectangular ductwork. They operate in airflow speeds of 100 to 4,000 fpm, in temperatures of –4 to 158 °F, and a humidity range of 0 to 95% (non-condensing). Their plug-in sensor heads offer improved false-alarm immunity and simple installation, testing, and maintenance. An improved cover design isolates the sensor head from the low-flow feature for simple maintenance. The InnovairFlex® housings provide ample wiring space, 3/4-inch conduit knockouts, and built-in short-circuit protection to prevent damage to sensitive components during installation.

High-contrast terminal designations make wiring easy. With its 2:1 sensor-to-power capability, the power board of the D4240 may be used to monitor a second sensor, D4S, simultaneously (i.e., supply and return side). As many as 50 InnovairFlex detectors can be interconnected. When one unit senses smoke, all interconnected detectors will switch their relays; only the detector sensing smoke will go into alarm, enabling the fire location to be pinpointed.

Features:

• 4-Wire Photoelectric, integrated low-fl ow technology
• Air velocity rating from 100 ft/min to 4,000 ft/min (0.5 m/s to 20.32 m/sec)
• Versatile mounting options: square or rectangular configuration
• Plug-in sensor and latest sensor technology help prevent false alarms
• Broad ranges for operating temperature (–4°F to 158°F) and humidity (0% to 95% non-condensing)
• Patented sampling tube installs from front or back of the detector with no tools required
• Increased wiring space with an additional ¾-inch conduit knockout
• One easy-access Test/Reset button and improved LED status
• Patented interconnect feature for multi-fan shutdown
• High-contrast terminal designations
• Built-in short circuit protection from operator wiring errors
• Field-selectable settings for confi guring the detector
• Two DPDT Form-C relay contacts
• 24 VAC/DC or 240 VAC
• Backward compatibility with existing System Sensor products, including remote accessories