Models 2WTR-B and 2WTA-B are 2-wire photoelectric smoke detectors; models 4WTR-B, 4WTA-B, 4WTAR-B, and 4WITAR-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. All models 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.

Models 2WTA-B, 4WTA-B, 4WTAR-B, and 4WITAR-B contain a piezoelectric horn which generates the ANSI S3.41 temporal pattern in an alarm condition. All detectors on a zone will sound when the power supply to them is reversed. The RRS-MOD can be used for the power supply reversal function. The RRS-MOD also enables all the detectors’ sounders on a zone to be synchronized and allows the zone to be silenced from the panel by entering the alarm silence key at the keypad.

The detector that initiated the alarm condition will have its red LED and Form C relays (if applicable) latched until reset by panel.

The model 4WITAR-B photoelectronic smoke sensor is isolated from the fixed-temperature heat sensor, providing a self-resetting, local audible smoke alarm that does not alarm at the panel. Only the fixed-temperature heat sensor will cause the 4WITAR-B to initiate an alarm at the panel and the relay to change its state.