System Sensor D4S InnovairFlex 4-Wire Photoelectric Duct Smoke Sensor Component, Requires D4120 or D4P120 Power Board

System Sensor D4S — InnovairFlex 4-wire photoelectric duct smoke sensor component, supplied without a power board.

Installation instructions I56-2967-002R state that the D4120 duct detector consists of the D4P120 power board and the D4S sensor component. This is the sensing half only: four wiring terminals and no power board, so it carries none of the alarm initiation, auxiliary or supervisory relay contacts a complete detector provides, and cannot be used alone. It wires to the Sensor 2 terminals of a D4120 or D4P120, which then watches two sensors at once, typically supply and return side.

• Sensor component only; an accessory to the D4120 in the ordering table
• Footprint 7.75 x 5 x 2.5 in. (19.7 x 12.7 x 6.35 cm)
• Operating -4 to 158 °F; air velocity 100 to 4,000 ft/min; 0 to 95 percent RH
• Four terminals with clamping plates, marked Tamper (Y,Y), +R and -B
• One D4120 with one D4S, or one D4P120 with two D4S units

The complete detector is the D4120; D4P120 is the power board alone and 2D51 the bare head. Sampling tubes DST1 to DST10 are marked sold separately and chosen by duct width.