System Sensor 2W-B Photoelectric i3 Smoke Detector, 2-Wire

Overview

The System Sensor 2W-B is a two-wire photoelectric smoke detector from the i3 Series. The design ensures reliable fire detection in open areas. You can use it in commercial, residential, and light-industrial settings. The detector uses light-scattering photoelectric sensing. It has a sensitivity of 2.5% per foot of obscuration. You can plug it into a pre-wired base without difficulty. The Stop-Drop 'N Lock method allows for quick installation and removal during service.

Technical Details

The 2W-B runs on a 12/24 VDC non-polarized circuit. It needs at least 8.5V and can handle up to 35V. In standby, it draws 50 µA. During an alarm, it uses up to 130 mA, controlled by the panel. Drift compensation and smoothing algorithms adjust for dust in the sensing chamber. This helps reduce false alarms between service intervals. The unit is UL 268 listed for Fire Protective Signaling Systems. It also has more listings from FM, MEA, MSFM, and cETLus agencies.

Installation & Application

The detector's base fits on 3.5-inch and 4-inch octagonal, single-gang, and 4-inch square backboxes with a plaster ring. It can also mount directly to the ceiling with drywall anchors. Wiring terminates via SEMS screws accepting 14-22 AWG wire through a large entry port. The 2W-B works with the 2W-MOD2 loop test module or an i3-compatible panel. This setup allows remote maintenance signaling and the EZ Walk loop test. Technicians can check the loop wiring from the panel, eliminating the need to test each detector individually.

Comparative Positioning

Within the i3 Series lineup, the 2W-B serves as the base two-wire photoelectric model. Facilities needing fixed-temperature heat detection can upgrade to the 2WT-B. It has a 135°F thermal sensor and a 41°F freeze-trouble indicator. For four-wire circuits, you can use the 4W-B and 4WT-B models.