System Sensor 4WT-B 4-Wire Smoke Detector and Heat Sensor

The System Sensor 4WT-B is an i3 Series conventional 4-wire photoelectric smoke detector with a 135°F fixed heat sensor, designed for fast installation and easy inspection using a plug-in, base-included design. It uses drift compensation and smoothing algorithms to help reduce nuisance alarms, with dual-color LED indication for quick local status checks. Key Specifications: Type: Conventional 4-wire photoelectric smoke and heat detector Core Function(s): Photoelectric smoke detection with fixed 135°F thermal sensing for added protection Loop/Protocol: Conventional 4-wire Power: 10 to 35 V, non-polarized; 50 µA max average standby Indicators/UI: Dual-color LEDs for power-up, standby, out-of-sensitivity, freeze trouble, and alarm status Operating Range: 32°F to 100°F (0°C to 37.8°C); 0 to 95% RH non-condensing Sensitivity: 2.5%/ft nominal Compatible Accessories: SENS-RDR – Sensitivity reader (percent-per-foot obscuration display) A77-AB2 – Retrofit adapter bracket System Compatibility: Works with conventional fire alarm control panels that support 4-wire smoke detectors and listed initiating circuits.