2WT-B

The Honeywell/System Sensor 2WT-B is a 2-wire photoelectric smoke detector with integrated 135°F (57°C) fixed-temperature thermal sensor from the i3 Series, providing dual-sensor fire detection for conventional fire alarm systems.
It features plug-in base mounting, drift compensation algorithms, sensitivity testing via optional reader, and LED status indicators (green standby/red alarm) with freeze trouble detection below 41°F (5°C).
Key Specifications
Feature
Details
Detection
Photoelectric smoke + 135°F fixed heat sensor 
Voltage
12/24VDC nominal (8.5-35V range), ≤30% ripple 
Standby Current
50µA average, 100µA peak 
Alarm Current
130mA max (panel-limited) 
Sensitivity
2.5%/ft nominal obscuration 
Temperature Range
32°F-120°F (0°C-49°C), freeze trouble <41°F 
Humidity
0-95% RH non-condensing ​
Mounting
Plug-in base, octagonal/4" square/gang boxes