System Sensor 2WTR-B Smoke Detector

The System Sensor 2WTR-B is a commercial 2-wire smoke detector designed for compatible conventional fire alarm systems. As part of the i3 Series, it combines smoke detection with an integrated 135°F (57.2°C) fixed-temperature heat sensor and a built-in Form C alarm relay, providing dependable fire detection and auxiliary control capabilities in a single device.

The detector features automatic drift compensation, dual-color LED status indication, a plug-in detector design, and installer-friendly maintenance features that help reduce service time while improving long-term reliability. This product is intended exclusively for commercial fire alarm installations.

Product Functions

• Detects airborne smoke
• Integrated 135°F fixed-temperature heat detection
• Built-in Form C alarm relay
• Automatic drift compensation
• Continuous smoke monitoring
• Dual-color LED status indication
• Magnetic functional testing
• Maintenance signaling with compatible modules

Electrical & System Information

The 2WTR-B operates on compatible 12/24 VDC non-polarized 2-wire initiating device circuits with an operating voltage range of 8.5–35 VDC. Automatic drift compensation and smoothing algorithms continuously adjust detector sensitivity to maintain reliable performance throughout its service life.

When used with the optional 2W-MOD2 maintenance module, the detector provides remote maintenance indication and loop testing from the fire alarm control panel. The integrated Form C relay allows auxiliary control functions without requiring an external relay module.

Features

• Commercial 2-wire smoke detector
• Integrated 135°F thermal sensor
• Built-in Form C relay
• Automatic drift compensation
• Dual-color LED indicators
• Plug-in detector head
• Low-profile housing
• Magnetic test capability
• Removable insect screen
• Stop-Drop ‘N Lock™ installation
• Remote maintenance capability
• Freeze trouble indication

Mounting & Design

The 2WTR-B includes an integrated mounting base compatible with 3½-inch and 4-inch octagonal boxes, single-gang boxes, and 4-inch square electrical boxes with plaster rings. It may also be mounted directly to the ceiling using the supplied drywall anchors where permitted by local codes.

Its plug-in detector head allows quick removal for inspection, cleaning, testing, or replacement without disturbing installed field wiring.

Protection & Applications

Suitable for:

• Office Buildings
• Schools
• Hospitals
• Hotels
• Retail Facilities
• Warehouses
• Government Buildings
• Industrial Facilities
• Commercial Properties

Compatibility

Compatible with:

• Conventional Fire Alarm Control Panels
• 2-Wire Initiating Device Circuits
• 2W-MOD2 Maintenance Module
• RRS-MOD Reversing Relay/Synchronization Module
• SENS-RDR Sensitivity Reader
• Compatible Auxiliary Relay Applications

Always verify compatibility with the installed fire alarm control panel, initiating device circuit, relay application, and project requirements before installation.

Technical Specifications

Manufacturer: System Sensor

Parent Company: Honeywell

Model: 2WTR-B

Series: i3 Series

Product Type: Commercial 2-Wire Smoke Detector

Detection Method: Photoelectric Smoke Sensing with Fixed-Temperature Heat Detection

Heat Sensor Rating: 135°F (57.2°C) Fixed Temperature

Relay Type: Form C Alarm Relay

Circuit Type: 2-Wire Conventional

Operating Voltage: 8.5–35 VDC (12/24 VDC Nominal)

Maximum Ripple Voltage: 30%

Average Standby Current: 50 µA

Peak Standby Current: 100 µA

Maximum Alarm Current: 130 mA (Limited by Control Panel)

Relay Contact Rating: Form C, 2 A @ 30 VAC/DC

Smoke Sensitivity: 2.5% Obscuration per Foot (Nominal)

Status Indicators: Dual-Color LEDs

Operating Temperature: 32°F to 100°F (0°C to 37.8°C)

Freeze Trouble Threshold: 41°F (5°C)

Operating Humidity: 0%–95% RH Non-Condensing

Wire Size: 14–22 AWG

Dimensions: 5.3 in. Diameter × 2.0 in. Height

Approximate Weight: 7.1 oz (200 g)

Mounting: Integrated Plug-In Base

Application: Indoor Commercial Fire Alarm Systems

Listings: UL 268, FM Approved, CSFM Listed, and other regional approvals where applicable. Verify product labeling and project requirements for the intended installation.

Applications

The System Sensor 2WTR-B is designed for commercial fire alarm systems requiring dependable smoke detection with integrated thermal sensing and relay functionality on conventional two-wire initiating device circuits. Typical applications include offices, schools, hospitals, hotels, retail facilities, warehouses, industrial buildings, government facilities, and other commercial occupancies utilizing compatible conventional fire alarm systems.

2WTR-B