Title: BELIMO NFB24-S Spring Return Damper Actuator, 24V On/Off with Auxiliary Switch

Product Overview:
The BELIMO NFB24-S is a high-performance, compact spring return damper actuator designed for reliable and precise control of air dampers in HVAC systems. Engineered for fail-safe operation, this actuator ensures that the damper returns to a pre-defined position (open or closed) upon power interruption, making it ideal for critical ventilation, zone control, and safety applications. Operating on a versatile 24 VAC/DC power supply, the NFB24-S provides robust 95 in-lb (10 Nm) torque, suitable for controlling dampers up to approximately 22 sq ft (2.0 m²). Its integrated auxiliary switch offers valuable feedback or control capabilities for other system components, enhancing overall building automation and energy management. With direct coupling for easy installation and Belimo's renowned quality, the NFB24-S delivers exceptional durability, energy efficiency, and quiet operation for commercial and industrial HVAC environments.

Key Features & Benefits:

 Fail-Safe Spring Return: Automatically drives the damper to a safe position (open or closed) during power outages, crucial for fire/smoke control and critical ventilation.
 High Torque Output: Delivers 95 in-lb (10 Nm) of torque, capable of handling dampers up to 22 sq ft (2.0 m²), ensuring reliable air flow control.
 Versatile Power Supply: Operates on 24 VAC/DC, simplifying integration into various low-voltage control systems.
 On/Off (2-Position) Control: Provides simple yet effective two-position control for basic damper operations.
 Integrated Auxiliary Switch: Features one SPDT auxiliary switch for position indication, interlocking with other equipment (e.g., fan status), or sequence control.
 Manual Override Button: Allows for temporary manual positioning of the damper for testing, maintenance, or emergency situations.
 Direct Coupling: Simplifies installation by directly mounting onto the damper shaft, eliminating the need for complex linkages.
 Low Power Consumption: Designed for energy efficiency, reducing operational costs and environmental impact.
 Quiet Operation: Ensures minimal noise disruption, making it suitable for noise-sensitive environments.
 Robust Construction: Built with high-quality materials for long-term reliability and performance in demanding HVAC applications.

Applications:

 Air handling units (AHUs)
 Variable Air Volume (VAV) boxes
 Zone control dampers
 Fresh air intake and exhaust dampers
 Return air dampers
 Smoke control systems (where applicable for general ventilation, not primary fire/smoke rated actuators)
 Building automation systems (BAS)
 Commercial and institutional HVAC systems (offices, schools, hospitals, retail)
 Energy management and optimization strategies

Technical Specifications:

 Part Number: NFB24-S
 Alternate Part Number: NFB24S
 Power Supply: 24 VAC/DC, 50/60 Hz
 Power Consumption:
 Running: 2.5 W
 Holding: 1.0 W
 Torque: 95 in-lb (10 Nm)
 Control Type: On/Off (2-position)
 Rotation Angle: 95°
 Running Time:
 Motor: 75-150 seconds
 Spring: 20 seconds
 Auxiliary Switch: 1 x SPDT, 7A resistive @ 250 VAC
 Shaft Diameter Range: 1/4" to 1/2" round, 1/4" to 3/8" square
 Enclosure Rating: NEMA 2 / IP42
 Ambient Operating Temperature: -22°F to 122°F (-30°C to 50°C)
 Ambient Humidity: 5 to 95% RH, non-condensing
 Weight: 2.5 lbs (1.1 kg)
 Certifications: UL, cUL Listed