Notifier FST-851R Heat Detector

The Notifier FST-851R is a commercial heat detector designed for compatible Notifier addressable fire alarm systems. It combines 135°F (57°C) fixed-temperature detection with rate-of-rise heat sensing, providing dependable thermal detection for areas where smoke detectors may not be suitable.

The detector features rotary decimal addressing, dual status LEDs, plug-in installation, and continuous communication with compatible Notifier control panels for alarm reporting and device supervision. This product is intended exclusively for commercial fire alarm installations.

Product Functions

• Fixed-temperature heat detection
• Rate-of-rise heat detection
• Reports alarm conditions to the fire alarm control panel
• Individual device identification
• Continuous device supervision
• Dual LED status indication
• Supports magnetic functional testing
• Automatic maintenance monitoring

Electrical & System Information

The FST-851R operates on compatible Notifier signaling line circuits with an operating voltage range of 15–32 VDC. Rotary decimal switches allow simple address assignment, while the fire alarm control panel continuously supervises detector status and communication.

The detector supports both FlashScan® and CLIP communication protocols when used with compatible control panels. A compatible detector base is required and may be sold separately.

Features

• Commercial heat detector
• 135°F (57°C) fixed-temperature sensing
• Rate-of-rise detection exceeding 15°F/minute
• Rotary decimal addressing
• Dual LEDs with 360° visibility
• Plug-in detector head
• Magnetic test capability
• Low-profile white housing
• Remote LED annunciator support
• Continuous electronic supervision

Mounting & Design

The FST-851R installs on compatible B210LP or B501 detector bases. Its plug-in design allows installation, inspection, testing, and replacement without disturbing field wiring, helping reduce maintenance time and simplify servicing.

Protection & Applications

Suitable for:

• Mechanical Rooms
• Boiler Rooms
• Warehouses
• Commercial Kitchens
• Loading Docks
• Utility Rooms
• Manufacturing Facilities
• Parking Structures
• Industrial Buildings

Compatibility

Compatible with:

• Notifier ONYX Fire Alarm Control Panels
• FlashScan Signaling Line Circuits
• CLIP Signaling Line Circuits
• B210LP Detector Base
• B501 Detector Base
• B224RB Relay Base
• B224BI Isolator Base
• B200S Sounder Base
• RA400Z Remote LED Annunciator
• RA100Z Remote LED Annunciator

Always verify compatibility with the installed fire alarm control panel, detector base, firmware version, and project requirements before installation.

Technical Specifications

Manufacturer: Notifier

Parent Company: Honeywell

Model: FST-851R

Product Type: Commercial Heat Detector

Detection Method: Fixed Temperature and Rate-of-Rise

Fixed Temperature Rating: 135°F (57°C)

Rate-of-Rise Response: Greater than 15°F (8.3°C) per Minute

Operating Voltage: 15–32 VDC Peak

Typical Standby Current: 300 µA @ 24 VDC

LED Current: 6.5 mA @ 24 VDC

Addressing: Rotary Decimal Switches

Status Indicators: Dual LEDs

Operating Temperature: –4°F to 100°F (–20°C to 38°C)

Operating Humidity: 10%–93% RH Non-Condensing

Maximum Detector Spacing: 50 ft (15.2 m) Centers

Mounting: B210LP or B501 Compatible Detector Base

Housing Color: White

Application: Indoor Commercial Fire Alarm Systems

Listings: UL Listed, ULC Listed, FM Approved, CSFM, MEA Listed, and additional regional approvals (application dependent).

Applications

The Notifier FST-851R is designed for commercial fire alarm systems requiring dependable thermal detection in environments where smoke detection may be impractical. Typical applications include mechanical equipment rooms, boiler rooms, commercial kitchens, warehouses, loading docks, utility spaces, manufacturing facilities, parking structures, and other commercial or industrial areas requiring fixed-temperature and rate-of-rise heat detection.

FST-851R Datasheet