Belimo TFRB24-SR Actuator

The Belimo TFRB24-SR is a compact spring return actuator designed for the fail-safe operation of dampers and valves in HVAC systems. Providing 22 in-lb torque, this proportional control actuator operates on a 24VAC/DC power supply and accepts a 2-10 VDC control signal for precise modulation. Built for high-reliability applications, it features brushless DC motor technology, ensuring consistent torque delivery and energy efficiency while eliminating the need for limit switches. The rugged housing is NEMA 2 rated, making it suitable for demanding mechanical room environments. When power is lost, the integrated mechanical spring return drives the application to its safety position, providing essential fail-safe protection. Field installation is streamlined via a universal shaft clamp and an adjustable angle of rotation, allowing for seamless integration into existing building automation systems (BAS) and pneumatic-to-electronic retrofits.

Key Benefits for Contractors

• Precise Modulation: Responds accurately to 2-10 VDC signals for tight control of airflow and fluid dynamics.
• Mechanical Fail-Safe: Reliable spring return mechanism ensures the damper or valve closes or opens during power loss.
• Low Power Consumption: Efficient brushless motor reduces operational costs and transformer sizing requirements.
• Simplified Installation: Universal mounting bracket and compact footprint facilitate HVAC retrofit projects in tight spaces.
• Maintenance-Free Operation: Rated for 60,000 cycles, providing long-term performance without the need for periodic adjustments.

Common Questions

Can the direction of the spring return be reversed?
Yes, the direction of the fail-safe operation (clockwise or counter-clockwise) is determined by the orientation of the actuator mounting on the shaft.

What happens if the actuator encounters an obstruction?
The Belimo TFRB24-SR is electronically protected against overload; it will stall at its end position or upon hitting an obstruction without damaging the gear train.

Does this unit require a specific transformer?
It requires a Class 2 24V power supply. Always calculate total VA draw when multiple actuators are wired to a single transformer to ensure stable proportional control.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.