Smoke Detector, 4-wire, Photoelectronic

MFR PART #  2D51
PART #  674090
Minimum 1 Each
In Stock


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 Annuiators with Piezo Alarm can also be connected to the D4P120 power board to provide an audible and visible indication of smoke detector status.

Must be a reseller to purchase this product.


  • 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 SERDR
  • 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 anlarm relays
  • Accepts 24 or 120V supply voltage
  • Interconnect up to 100 units for common functions
  • Compatible for interconnection with System Sensor InnoviarFlex(TM) D4120 or D4120W duct smoke detectors and remote accessories


UNSPSC Code 46171600

Spec Sheet

Spec Sheet

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