System Sensor 2D51 4-wire photo replacement head

The System Sensor 2D51 low-profile photoelectric smoke detector with a B210LP base tied to the D4P120 is listed to Underwriters Laboratories 268A specifically for use in no-flow/low-flow air-handling systems

The 2D51 can be used as a pendant mount detector in no-flow/ low-flow air-handling systems (0-4,000 FPM). The pendant /plenum mounted 2D51 is to be installed into a B210LP base and wired to a D4P120 power board-only control unit. The D4P120 power board is capable of controlling up to two 2D51 sensors.

Pendant mounted in a standard electrical box within the duct, the twist-in/twist-out head allows easy removal from the base for quick cleaning and maintenance. The 2D51 heads can be locally tested using a magnet or by using the test/reset push button on the D4P120 power board.

Remote testing is accomplished using the RTS151, RTS151KEY, RTS-2 or RTS-AOS accessories connected to the D4P120 power board.

The APA151, RTS2 and RTS2-AOS Remote Annunciators with Piezo Alarm can also be connected to the D4P120 power board to provide an audible and visible indication of smoke detector status.

Features for 2D51/B210LP/D4P120
• Low-profile smoke detector design
• Low standby current
• Two LEDs blink in standby
• Detector head plugs easily into base
• Built-in test switch
• Field sensitivity metering of detector to meet the requirements of NFPA 72 with the use of RTS2/RTS2-AOS and SENS-RDR
• Designed for mounting on a standard electrical box
• SEMS screws for easy wiring and positive wire retention
• Removable cover and insect screen for field cleaning
• Remote push button Test/Reset, LEDs provide visual indications
• Onboard supervisory and alarm relays
• Accepts 24 or 120V supply voltage
• Interconnect up to 100 units for common functions
• Compatible for interconnection with System Sensor InnoviarFlex™ D4120 or D4120W duct smoke detectors and remote accessories