Models 2W-B and 2WT-B are 2-wire photoelectric smoke detectors; models 4W-B and 4WT-B are 4-wire photoelectric smoke detectors. All models incorporate a state-of-the-art optical sensing chamber and an advanced microprocessor. The microprocessor allows the detector to automatically adjust its sensitivity back to the factory setting when it becomes more sensitive due to contaminants settling in its chamber. In order for this feature to work properly, the chamber must never be opened while power is applied to the smoke detector. This includes cleaning, maintenance or screen replacement. Should it become necessary, the screen/sensing chamber is field replaceable. Models 2WT-B and 4WT-B also feature a restorable, built-in, fixed temperature (135°F) thermal detector and are also capable of sensing a freeze condition if the temperature is below 41°F.

All i3 Series detectors are designed to provide open area protection. Two-wire models must be used with compatible UL Listed panels only.

When used with an i3 Series compatible control panel or the i3 Series 2W-MOD module (refer to installation manual D500-46-00), the 2W-B and 2WT-B are capable of generating a “maintenance needed” signal. The 2W-MOD can indicate a need for cleaning, replacement, or a freeze condition (2WT-B only) at the control panel or module.

Installation of the 2W-B, 2WT-B, 4W-B, and 4WT-B detectors is simplified by the use of a mounting base that may be pre-wired to the system, allowing the detector to be easily installed or removed. The mounting base installation is further simplified by the incorporation of features compatible with drywall fasteners.