The Belimo SM24A-SR is the 20 Nm big brother of the NM24A-SR — a modulating damper actuator with 2–10 V control and 2–10 V feedback, for proportional control of larger air dampers up to approximately 4 m². It delivers ±5% positioning accuracy, a 150-second running time and a lockable manual override, running on AC/DC 24 V. Note its mechanical interface is a reversible universal clamp for 10–20 mm shafts. This is the model for BMS-controlled modulating dampers where 10 Nm isn’t enough torque. Choose it when you need proportional control on a larger damper; select torque on the damper manufacturer’s requirement, not simply the highest available. Confirm shaft size, damper torque and a modulating BMS output before ordering.
| Spec | Detail |
|---|---|
| Model | Belimo SM24A-SR |
| Torque | 20 Nm |
| Voltage | AC/DC 24 V |
| Control | Modulating |
| Signal / feedback | 2–10 V / 2–10 V |
| Input impedance | 100 kΩ |
| Position accuracy | ±5% |
| Power (run/rest/sizing) | 2 W / 0.4 W / 4 VA |
| Connection | Cable 1 m, 4×0.75 mm² |
| Running time | 150 s / 90° |
| Angle of rotation | Max 95° (limitable) |
| Sound power | 45 dB(A) |
| Mechanical interface | Reversible clamp 10–20 mm |
| Protection | IP54 / NEMA 2 / Class III (SELV) |
| Ambient | −30…50°C |
| Weight | 0.95 kg |
| Certification | IEC/EN 60730-1 & -2-14; VDI 6022 |
| Air damper size | Up to approx. 4 m² |
