System Sensor 4W-B i3 4-Wire Photoelectric Smoke Detector

The System Sensor 4W-B is the four-wire version of the i3 photoelectric detector, separating detector power from the alarm contacts used by the control panel. That architecture can suit existing four-wire fire zones and retrofit layouts where a compatible end-of-line power-supervision relay is part of the design.

The detector automatically compensates for gradual contamination in the optical chamber and uses smoothing algorithms to reject short disturbances. Its removable cover and chamber support scheduled cleaning, while the red and green LEDs make standby, out-of-sensitivity, and alarm conditions visible from the floor.

A pre-wired plug-in base helps service work stay orderly, but the circuit still needs a correct power-reset method and supervision arrangement. In an existing alarm system takeover, verify every conductor and end-of-line device before deciding whether a 4W-B is a compatible replacement. The completed zone is smoke-tested and confirmed at the panel and monitoring station.