Description
The Belimo EFB24-SR N4 is a high-torque spring return damper actuator delivering 270 in-lb of force for precise modulating airflow control. Operating on AC/DC 24 V with a 2…10 V control signal, it provides reliable fail-safe performance in demanding HVAC and industrial environments.
Technical Specifications
| Condition |
New/Never Used Surplus |
| Brand |
Belimo |
| Category |
Actuators & Dampers |
| Part Number |
EFB24-SR N4 |
| Subcategory |
Damper Actuators |
| Actuator Type |
Spring return, modulating |
| Nominal Torque |
270 in-lb (30 Nm) |
| Nominal Voltage |
AC/DC 24 V |
| Nominal Frequency |
50/60 Hz |
| Voltage Range |
AC 19.2…28.8 V / DC 21.6…28.8 V |
| Control Signal |
2…10 V (4…20 mA with resistor) |
| Power Consumption (Running) |
8 W |
| Power Consumption (Rest) |
4.5 W |
| Transformer Sizing |
14 VA |
| Angle of Rotation |
Adjustable 35…95° |
| Running Time |
95 s / 90° |
| Fail-Safe Running Time |
<20 s |
| Electrical Connection |
Terminal blocks in NEMA 4 junction box |
| Degree of Protection |
IP66 / NEMA 4 |
| Ambient Temperature |
-22…122°F (-30…50°C) |
| Weight |
12 lb (5.3 kg) |
Information About EFB24-SR N4
The EFB24-SR N4 is part of Belimo’s heavy-duty spring return damper actuator range engineered for applications requiring high torque and enhanced environmental protection. It features a sealed enclosure rated IP66 and NEMA 4, supporting installation in wash-down areas, outdoor locations, and harsh mechanical environments. The actuator operates on AC/DC 24 V and supports precise modulating control with 2…10 V input, along with position feedback for closed-loop control systems. Designed for maintenance-free service, it combines robust mechanical construction with electronic overload protection to ensure reliable long-term performance.
Key Features
- High Torque Spring Return Actuation: Delivers 270 in-lb (30 Nm) of torque to reliably operate large or high-resistance dampers under demanding conditions.
- Fail-Safe Spring Return Function: Integrated spring mechanism automatically drives the damper to a predefined safety position during power loss.
- Precise Modulating Control Capability: Supports 2…10 V control signals with optional 4…20 mA input for accurate and stable airflow modulation.
- Rugged Environmental Protection: IP66 and NEMA 4 enclosure ratings protect internal components from dust, moisture, and wash-down exposure.
- Adjustable Mechanical Stroke: Mechanical end stops allow angle-of-rotation adjustment between 35° and 95° to match damper travel requirements.
- Integrated Position Feedback: Provides a 2…10 V feedback signal for continuous damper position monitoring and control optimization.
- Service-Friendly Design: Includes a 5 mm hex manual override and electronic overload protection for safe commissioning and dependable operation.
The EFB24-SR N4 delivers the reliability and precision required for high-torque, fail-safe, and modulating damper control in commercial and industrial HVAC systems.
