Notifier NFX-TDIFF-IV Opal Rate-of-Rise Heat Detector (A1R, Ivory)

The Notifier NFX-TDIFF-IV is an Opal NFX-series analogue addressable rate-of-rise heat detector. This is the ivory version without an isolator. It gives an alarm when the temperature rises faster than 10 °C per minute (typical) or when it exceeds a fixed threshold of 58 °C (response class A1R).

Heat detectors like this suit fires with little smoke but a rise in temperature, in areas such as boiler rooms, cold stores, poorly ventilated enclosed car parks and areas next to kitchens.

Key features

• Rate-of-rise (10 °C/minute) and fixed 58 °C alarm thresholds, class A1R
• Two integral tri-colour LEDs (red, green and amber) for 360° local status indication
• Rotary decade address switches
• Opal digital protocol, allowing up to 159 devices and modules per loop, with reduced loop power consumption
• 100% mechanical and electrical backwards compatibility with earlier Notifier series
• Low-mass thermistor with microprocessor processing for fast, linear temperature sensing
• Ivory finish; no isolator
• Accessories include the B501AP base, WB-1AP weatherproof cap, SMK400EAP surface kit and RMK400AP recess kit

Technical specifications

• Operating voltage: 15 to 32 V DC
• Standby current: 200 µA at 24 V DC (no communication); 300 µA at 24 V DC (LED blinking)
• LED current at 24 V DC: 3.5 mA red, 7.0 mA green, 10.5 mA amber
• Operating temperature: -30 °C to +70 °C
• Relative humidity: 10% to 93%, non-condensing
• Height: 61 mm installed in a B501AP base
• Diameter: 102 mm
• Weight: 88 g
• IP rating: IP30 (IP33 with WB-1AP)
• Cable size: 2.5 mm²
• Material: PC/ABS
• Standard: EN 54-5