The IQ651H is an intelligent, addressable heat detector combining fixed-temperature and rate-of-rise detection in a single slim-profile unit. UL listed to UL 521 and FM Approved for indoor fire protective signalling systems, it delivers reliable early heat detection with the precision of addressable technology.

Dual Detection, Smarter Response
The IQ651H triggers an alarm when temperature reaches the fixed threshold of 135°F (57°C), or when it detects a rapid rate-of-rise of 15°F/min (8.3°C/min) — catching fast-developing fires before they reach critical levels. An onboard Microcontroller Unit (MCU) continuously runs self-diagnostic tests to ensure the detector is always operational.

Addressable Intelligence
Taking a single address on the Signalling Line Circuit (SLC), the IQ651H reports its exact location and status directly to the fire alarm control panel, enabling fast, accurate response. Supports both Class A and Class B circuit configurations.

Key Specifications

• Nominal Voltage: 24 VDC (Range: 17.6–28 VDC)
• Fixed Temperature Rating: 135°F (57.5°C)
• Rate-of-Rise Detection: 15°F/min (8.3°C/min)
• Operating Temperature: 0°C to 38°C (32°F to 100°F)
• Humidity: 0–93% RH
• Diameter: 105 mm | Height: 47.5 mm | Weight: 121 g
• Mounting: Ceiling or wall | Max spacing: 15 m (50 ft)
• Ingress Protection: IP-43

Certifications: UL Listed (UL 521) | FM Approved