FW2521 - UL 521 Compliant Thermal Detection
Fixed Temperature • Rate-of-Rise • Intelligent Thermal Sensing
FW2521
The FW2521 Intelligent Heat Detector is a high-performance thermal detection device designed for environments where smoke detectors are not suitable due to dust, humidity, or temperature extremes. Utilizing dual sensing technology (fixed temperature and rate-of-rise), it provides reliable fire detection in challenging conditions while minimizing false alarms.
| Model Number | FW2521 |
| Product Name | Intelligent Heat Detector |
| Detection Type | Dual Element (Fixed Temp + Rate-of-Rise) |
| Fixed Temperature Settings | 135°F, 174°F, 190°F (57°C, 79°C, 88°C) |
| Rate-of-Rise Setting | 15°F/min (8.3°C/min) minimum |
| Certification | UL 521, NFPA 72 |
| Manufacturer | Maple Armor / Tongfang BMS |
| System Compatibility | Addressable Fire Alarm Systems |
| Communication Protocol | Digital, Two-Wire |
| Operating Voltage | 15-32VDC |
| Standby Current | 350μA @ 24VDC |
| Alarm Current | 40mA @ 24VDC |
| Alarm Indication | Red LED (360° Visible), Bi-color Status LED |
| Test Method | Magnet Test, Heat Test Tool |
| Operating Temperature Range | -40°F to 150°F (-40°C to 66°C) |
| Storage Temperature | -40°F to 160°F (-40°C to 71°C) |
| Relative Humidity | 0% to 95% RH (Non-condensing) |
| Dimensions | 4.5" diameter x 2.1" height (114mm x 53mm) |
| Weight | 4.5 oz (128 g) |
| Color | White (Standard), Ivory, Gray options |
| Mounting | Ceiling or Wall Mount |
| Terminals | Screw terminals, 12-22 AWG wire |
| IP Rating | IP54 (Dust and splash resistant) |
| Warranty | 5-Year Limited Warranty |
| Calibration Interval | Annual recommended |
Standard setting
High temperature areas
Industrial applications
The FW2521 Intelligent Heat Detector is specifically designed for environments where smoke detectors are impractical or prone to false alarms. Utilizing dual-element thermal sensing technology, it combines fixed temperature detection with rate-of-rise monitoring to provide comprehensive fire protection in challenging conditions such as kitchens, garages, workshops, and industrial facilities.
Compliant with UL Standard 521 for Heat Detectors, ensuring reliable performance in thermal detection applications.
Combines fixed temperature and rate-of-rise detection for comprehensive fire monitoring in challenging environments.
Advanced processing distinguishes between normal temperature variations and fire conditions, reducing false alarms.
Activates when ambient temperature reaches preset threshold (135°F, 174°F, or 190°F).
Detects rapid temperature increases exceeding 15°F per minute, providing early warning.
Analyzes temperature patterns to distinguish between normal variations and fire conditions.
UL 521: Standard for Heat Detectors
NFPA 72: National Fire Alarm Code
CSFM: California State Fire Marshal
CE: European Conformity
IBC: International Building Code
Local Codes: Complies with most local fire codes
15-32VDC, 350μA standby, 40mA alarm. Use fire-rated cable.
Two-wire addressable loop, polarity insensitive.
Screw terminals accept 12-22 AWG wire. Clearly marked terminals.
Place magnet on test point for 3 seconds to activate test mode.
Use approved heat test tool for functional temperature testing.
Ideal for kitchens where smoke from cooking would cause false alarms.
Perfect for manufacturing areas with dust, fumes, or high temperatures.
Reliable detection in areas with vehicle exhaust or workshop activities.
Code Compliance: Meets UL 521 and NFPA 72 requirements
Reliable Detection: Effective in challenging environments
Low False Alarms: Immune to dust, steam, and cooking aerosols
Cost Effective: Lower maintenance than smoke detectors
Easy Maintenance: Simple testing and cleaning
Versatile: Suitable for diverse applications
Monthly
Check for damage or obstructions
Semi-Annual
Test using magnet or heat test tool
Annual
Clean detector and verify operation