System Sensor 4WT-B

The System Sensor 4WT-B is a 4-wire i3 Series smoke detector that combines photoelectric smoke sensing with a 135F fixed-temperature thermal sensor in one head, powered from a 12/24VDC conventional circuit. It carries the i3 line's drift compensation and smoothing algorithms to reduce nuisance alarms, and its nominal sensitivity is 2.5% per foot as measured in the UL smoke box.

Key Features

• Combination photoelectric smoke + 135F fixed thermal detector, 4-wire (conventional)
• Plug-in base design allows pre-wiring bases before heads are installed
• i3 drift compensation and smoothing algorithms reduce nuisance alarms
• Wide-angle red/green LEDs indicate normal standby, out-of-sensitivity, alarm, or freeze trouble
• Readable with the SENS-RDR wireless sensitivity reader (percent-per-foot obscuration)

Technical Specifications

• Power: 12/24 VDC, 4-wire
• Thermal Element: 135F fixed temperature
• Sensitivity: 2.5%/ft nominal (UL smoke box)
• Operating Temperature: 32F to 120F
• Mounting: 3.5"/4" octagonal, single-gang, or 4" square boxes with plaster ring, or direct ceiling mount

Certifications

• UL Listed, meets CSFM standards