System Sensor 4WTAR-B Photoelectric i3 Smoke Detector, 4-Wire, Thermal Sensor, Built-In Sounder, Form C Relay

The System Sensor 4WTAR-B is a 4-wire i3 Series photoelectric smoke and heat detector with a built-in 85 dBA sounder, 135 F fixed-temperature thermal sensor, and Form C alarm relay for conventional fire alarm and security systems. Operating on 12/24 VDC, it features 2.5%/ft nominal smoke sensitivity, automatic drift compensation, dual-color status LEDs, and a 41 F freeze trouble indicator. The detector draws 50 A in standby and up to 50 mA during alarm, supports sounder synchronization using the optional RRS-MOD module, and includes a prewired mounting base with Stop-Drop 'N Lock installation technology.

System Sensor 4WTAR-B i3 4-Wire Smoke and Heat Detector with Sounder and Relay

The System Sensor 4WTAR-B is a conventional four-wire combination photoelectric smoke and fixed-temperature heat detector with an integrated audible sounder and Form C relay designed for commercial and residential fire protection applications. Part of the System Sensor i3 Series, the 4WTAR-B combines photoelectric smoke detection, a self-restoring 135 F (57.2 C) thermal sensor, and an 85 dBA piezoelectric sounder within a single ceiling- or wall-mounted assembly. Its photoelectric sensing chamber detects airborne smoke particles, while the integrated thermal element provides an additional means of identifying fire conditions when the specified temperature threshold is reached. The detector incorporates a Form C auxiliary relay rated at 2 amps at 30 VAC/DC for integration with compatible alarm and monitoring equipment. Designed for conventional fire alarm and security control panels, the 4WTAR-B provides local audible notification, supervised smoke and heat detection, and auxiliary alarm signaling for homes, offices, apartment buildings, commercial facilities, and other protected indoor environments.

The 4WTAR-B operates on nominal 12 or 24 VDC power with a manufacturer-specified operating voltage range of 10-35 VDC. Its low-power circuitry draws approximately 50 microamps during normal standby operation and up to 50 mA during alarm, allowing integration with appropriately rated conventional fire alarm control panels and power supplies. The photoelectric sensing chamber has a nominal smoke sensitivity of 2.5% obscuration per foot and incorporates microprocessor-controlled drift compensation and smoothing algorithms that automatically compensate for gradual contamination and reduce nuisance alarms caused by environmental interference. The integrated 135 F fixed-temperature thermal detector provides supplemental heat detection, while a 41 F (5 C) freeze trouble feature identifies temperatures below the detector's recommended operating conditions. Two status LEDs provide visual diagnostic information, with a flashing green indicator during normal standby, a solid red indicator during alarm, and distinctive red flashing patterns for sensitivity maintenance and freeze trouble conditions. In addition to its Form C auxiliary relay, the detector incorporates alarm contacts rated at 0.5 amps at 30 VAC/DC for connection to the conventional alarm initiating circuit.

The System Sensor 4WTAR-B features an integrated 85 dBA audible sounder that produces an ANSI S3.41 temporal-three evacuation signal when the detector enters an alarm condition. When installed with the optional System Sensor RRS-MOD reversing relay and synchronization module, the detector supports coordinated audible signaling across compatible i3 Series sounder detectors connected to the same circuit. The RRS-MOD reverses supply polarity to activate all compatible sounders when an alarm occurs, synchronizes their temporal alarm patterns, and enables supported sounder silencing from the fire alarm control panel. The 4WTAR-B also incorporates a Stop-Drop 'N Lock plug-in mounting system that allows installers to prewire the base before attaching the detector head. The included mounting base accommodates single-gang electrical boxes, 3-1/2-inch and 4-inch octagonal boxes, and 4-inch square boxes with plaster rings, as well as approved direct ceiling mounting. Its SEMS screw terminals accept 14-22 AWG conductors, providing flexible wiring connections for compatible fire alarm installations. An optional tamper-resistant locking feature helps prevent unauthorized detector removal, while the removable cover and optical sensing chamber simplify cleaning, inspection, and maintenance.

The System Sensor 4WTAR-B measures 5.3 inches in diameter and 2 inches high (134 x 51 mm), including its mounting base, and weighs approximately 7.1 ounces (200 grams). The detector operates in temperatures from 32 F to 100 F (0 C to 37.8 C) and supports relative humidity from 0% to 95%, noncondensing. Its smoke detection sensitivity can be measured using the separately available System Sensor SENS-RDR infrared sensitivity reader, allowing service technicians to verify detector sensitivity without removing the sensing head. The 4WTAR-B is UL 268 Listed for smoke detection in fire protection signaling systems and is intended for installations designed according to applicable NFPA 72 requirements and local fire codes. Unlike the System Sensor 4WTR-B, which includes a Form C relay without an audible sounder, and the 4WTA-B, which includes an audible sounder without a Form C auxiliary relay, the 4WTAR-B incorporates both functions. The related 4WITAR-B provides an isolated thermal configuration with different smoke and heat alarm signaling behavior. Combining photoelectric smoke sensing, fixed-temperature heat detection, 85 dBA audible notification, auxiliary relay contacts, drift compensation, and synchronized sounder capability, the 4WTAR-B provides an integrated conventional fire detection solution for compatible security and fire alarm systems.