The Opal NFXI-TFIX58 and NFXI-TFIX78 are analogue addressable fixed-temperature heat sensors that utilise low-mass thermistors combined with microprocessor technology to achieve rapid response and precise, linear temperature measurement. This linear performance enables accurate temperature detection at fixed thresholds of 58°C (Class A1S) and 78°C (Class BS).
The Opal NFXI-TDIFF employs the same thermistor and microprocessor design to initiate an alarm when the temperature rises at a rate exceeding 10°C per minute (typical), or when a temperature of 58°C is reached, meeting Response Class A1R requirements. Through Notifier’s Opal protocol, the device can be software configured as a fixed 58°C detector, a fixed 78°C detector, or a 58°C detector with rate-of-rise functionality. To ensure approval continuity and backwards compatibility, these configurations remain available as individual part numbers.
All three heat detectors feature sensing elements that are fully configurable via the Opal protocol, allowing the fire control panel to adjust sensitivity thresholds to suit changing environmental conditions. Each detector incorporates built-in short-circuit isolation and two integrated tri-colour LEDs, providing 360-degree visual status indication. LED operation is programmable, supporting steady or flashing red, amber, and green indications.
Key Features:
Integrated short-circuit isolation
Advanced Opal protocol enabling loop mapping for accurate fault identification
Tri-colour LED indicators (red, green, and amber)
Rotary decade address switches
Clean white finish to suit modern building designs
Full mechanical and electrical backwards compatibility
Base design optimised for simple installation and wiring