Product information "Belimo LRF24-SR Modulating Rotary Actuator for Ball Valves (24V, 4Nm, Fail-Safe)"
The Belimo LRF24-SR is a compact modulating rotary actuator designed for ball valve automation with a built-in spring return fail-safe function. The actuator follows a 2–10 VDC control signal to position the valve accurately and provides 2–10 VDC position feedback for BMS monitoring and control verification. On power interruption, the spring drives the valve to the fail-safe position (NC: closed).
It offers simple direct mounting with flexible orientation and includes a hand-crank manual override that can be fixed in any position for commissioning and service.
Applications
Modulating control of 2-way/3-way ball valves in HVAC water systems
Fail-safe shutoff (de-energised closed) for coils, branches, and isolation duties
BMS systems requiring 2–10 V control + 2–10 V feedback for monitoring and alarms
Retrofit or new installations needing IP54 protection and reliable spring return safety
Technical data
Specification
Value
Model
LRF24-SR
Application
Rotary actuator with fail-safe for ball valves
Supply
AC/DC 24 V, 50/60 Hz
Voltage range
AC 19.2–28.8 V / DC 21.6–28.8 V
Control signal (Y)
2–10 VDC
Input impedance
100 kΩ
Feedback (U)
2–10 VDC (max 0.5 mA)
Torque (motor)
4 Nm
Torque (fail-safe)
4 Nm
Fail-safe direction
De-energised NC (valve closed)
Running time (motor)
150 s / 90°
Fail-safe time
<20 s @ -20…50°C; <60 s @ -30°C
Power consumption
2.5 W (operation); 1 W (rest); 5 VA (wire sizing)
Connection
Cable 1 m, 4 × 0.75 mm²
Protection rating
IP54
Ambient
-30…50°C; max 95% RH non-condensing
Storage
-40…80°C
Manual override
Hand crank (fixable)
Service life
Min. 60,000 fail-safe cycles
Weight
1.5 kg
Documents
Datasheet Belimo LRF24-SR 24V modulating rotary actuator for ball valves
