027 04299 008 York Damper Actuator (NFB24)

Overview

The York 027 04299 008 (Belimo NFB24) is a high-performance, spring-return damper actuator designed for reliable on/off fail-safe control in commercial HVAC systems. Providing a minimum of 90 in-lb of torque, this actuator is engineered to drive dampers to a safe position during power interruptions. Its compact design and high efficiency make it an industry standard for both new installations and retrofit projects, capable of controlling damper surfaces up to approximately 22 square feet.

Features

• True spring-return mechanism ensures positive fail-safe positioning upon power loss
• Brushless DC motor technology provides precise control, high efficiency, and maintenance-free operation
• Electronic overload protection throughout the 0 to 95 degree rotation prevents motor damage without the need for limit switches
• Integrated manual override with a 5 mm hex crank allows for manual positioning and easy system testing
• Symmetrical design and universal shaft clamp support easy mounting for either clockwise or counter-clockwise fail-safe direction
• Visual mechanical position indicator provides clear status of the damper’s angle at a glance

Specifications

• Torque: 90 in-lb (10 Nm) minimum
• Power Supply: AC 24 V, 50/60 Hz; DC 24 V
• Power Consumption: 6 W (Running), 2.5 W (Holding)
• Transformer Sizing: 8.5 VA (Class 2 power source)
• Running Time (Motor): <75 seconds
• Running Time (Fail-Safe): <20 seconds at -4 to 122 F; <60 seconds at -22 F
• Angle of Rotation: Max 95 degrees, adjustable with mechanical end stops
• Enclosure Rating: NEMA 2, IP54, UL Enclosure Type 2
• Ambient Temperature Range: -22 to 122 F (-30 to 50 C)
• Electrical Connection: 3 ft, 18 GA appliance cable with 1/2 inch conduit connector

Applications

• On/off control of dampers in air handling units, makeup air units, and fan coil units
• Fail-safe operation for economizers and ventilation systems requiring reliable closure
• Control of larger damper surfaces up to 22 square feet in building automation systems
• Retrofit and replacement projects for older spring-return actuators in tight mechanical spaces