Belimo EFB24-SR
Damper Actuator, 270 in-lb [30 Nm], Spring return, AC/DC 24 V, 2...10 V, modulating

Product Details
For proportional modulation of dampers in HVAC systems. Actuator sizing should be done in accordance with the damper manufacturer’s specifications. The actuator is mounted directly to a damper shaft up to 1.05” in diameter by means of its universal clamp. A crank arm and several mounting brackets are available for applications where the actuator cannot be direct coupled to the damper shaft. The actuator operates in response to a 2 to 10 VDC, or with the addition of a 500 ohm resistor, a 4 to 20 mA control input from an electronic controller or positioner. A 2 to 10 VDC feedback signal is provided for position indication. Not to be used for a master-slave application.
The EFB24-SR uses a brushless DC motor which is controlled by an Application Specific Integrated Circuit (ASIC) and a microprocessor. The microprocessor provides the intelligence to the ASIC to provide a constant rotation rate and to know the actuator’s exact fail-safe position. The ASIC monitors and controls the brushless DC motor’s rotation and provides a digital rotation sensing function to prevent damage to the actuator in a stall condition. The actuator may be stalled anywhere in its normal rotation without the need of mechanical end switches.
Attributes
| Control | modulating |
| Fail-Safe | Spring Return |
| Torque | 270 in-lb |
| Nominal Voltage | AC/DC 24 V |
| Transformer Sizing | 14 VA (class 2 power source) |
| Enclosure | UL Enclosure Type 2 |
| Power Supply | 24 VAC, ±20%, 50/60 Hz, 24 VDC, -10% / +20% |
| Power Consumption In Operation | 8 W |
| Power Consumption In Rest Position | 4.5 W |
| Electrical Connection | 18 GA appliance cable, 3 ft [1 m], with ½” conduit connector |
| Overload Protection | electronic throughout 0…95° rotation |
| Operating Range | 2…10 V, 4…20 mA w/ ZG-R01 (500 Ω, ¼ W resistor) |
| Input Impedance | 100 kΩ for 2…10 V (0.1 mA), 500 Ω for 4…20 mA |
| Position Feedback | 2…10 V, Max. 0.5 mA |
| Angle Of Rotation | Max. 95°, adjustable with mechanical end stop, 35…95° |
| Direction Of Motion Motor | selectable with switch 0/1 |
| Position Indication | Mechanical |
| Running Time (Motor) | 95 s |
| Running Time Fail-Safe | <20 s |
| Ambient Humidity | max. 95% r.H., non-condensing |
| Ambient Temperature | -22…122°F [-30…50°C] |
| Storage Temperature | -40…176°F [-40…80°C] |
| Degree Of Protection Iec/En | IP54 |
| Degree Of Protection Nema/Ul | NEMA 2 |
| Connection | cable |
| Servicing | maintenance-free |
| Housing Material | Die cast aluminium and plastic casing |
| Nominal Voltage Dc | 24 V |
| Nominal Voltage Ac | 24 V |
| Noise Level, Motor | 56 dB(A) |
| Torque Motor | 270 in-lb [30 Nm] |
| Electrical Protection | actuators are double insulated |
| Quality Standard | ISO 9001 |
| Noise Level, Fail-Safe | 71 dB(A) |
| Angle Of Rotation Adaptation | manual, by two full cycles of 0/1 switch |
| Agency Listing | cULus acc. to UL60730-1A/-2-14, CAN/CSA E60730-1:02, CE acc. to 2014/30/EU Listed to UL 2043 - suitable for use in air plenums per Section 300.22(C) of the NEC and Section 602 of the IMC |
| Shaft Diameter | ½…1.05” round, centers on ¾” with insert, 1.05” without insert |
| Fail-Safe Function | Spring return |
| Control Type Web | DC 2…10 V |
| Fail-Safe | YES |
Specifications
| SKU | CS3035898 |
|---|---|
| MPN | EFB24-SR |











