Good points

Open/close and 3-point control
Rotation angle of up to 95°
Overload safe
IP54 protection class

Belimo rotary damper actuator 24V - open/close & 3-point - 20 Nm - SM24A

The Belimo SM24A is a rotary damper actuator designed for open/close or 3-point control of large air damper sections up to approximately 4 m². The actuator is powered by AC/DC 24 V and is suitable for simple two-point (on/off) as well as three-point control, allowing the damper to be held in an intermediate position. The actuator provides a torque of 20 Nm, making it ideal for large, heavy damper constructions in central air handling units. The motor achieves a 90° rotation in 150 seconds. Standby power consumption is only 0.2 W and the noise level is 45 dB(A).

Benefits and Features

20 Nm open/close and 3-point control: The 20 Nm torque makes the actuator suitable for large air damper sections up to approx. 4 m². Thanks to the 3-point control, the damper can also be held in an intermediate position without requiring an analogue control signal or proportional actuator.
Adjustable direction of rotation: The direction of rotation is easily selectable via a switch (left or right), allowing flexible installation and broad applicability.
Manual adjustment with lockable push button: Enables manual operation and locking during installation and maintenance.
Adjustable angle of rotation: The angle of rotation can be mechanically limited on both sides up to a maximum of 95°, allowing precise alignment of the actuator to the damper’s opening range.
Overload protection: Automatically stops at the end position, eliminating the need for separate end switches.
IP54 protection class: Protected against dust and splashing water from all directions, ensuring durability against daily environmental influences and a long service life.

Installation, Maintenance and Applications

The actuator is mounted directly onto the damper shaft using the supplied universal clamp ring, suitable for shaft diameters from 10 to 20 mm. The shaft must be at least 48 mm long and extend a minimum of 20 mm. The actuator includes a rotation lock to prevent unwanted movement. The angle of rotation can be set via mechanical stops on both sides, with a maximum of 95°. The direction of movement is easily adjustable with a switch (position 0 = counterclockwise, position 1 = clockwise). For manual adjustment, a lockable push button is provided. Electrical connection is via a fixed 1-metre cable with 3 cores (0.75 mm²).
The actuator is maintenance-free and is suitable for open/close or 3-point control of large damper sections in central air handling units, on/off controlled supply and exhaust dampers, mixing dampers, and fire dampers in commercial buildings and industrial HVAC systems.

Brand	Belimo
Category	Belimo valve drive
GTIN	7630498114403
Manufacturer's item number	SM24A
Article number	23010058

Specifications

Category code	101
Suitable for air accessory	Yes
Supply voltage	24 V AC/DC
Control signal	2-point/3-point
Energy consumption in operation	2 W
Energy consumption at rest	0.2 W
Model	Rotating
Regulation type on/off	Yes
Regulation type modulating	No
Regulation type splitrange	No
Connection cable length	1 m
Transmission	With cogwheels
With direct mount top flange according to ISO 5211	No
Return at zero supply voltage	No
Deactivated when closed	No
Automatic stroke recognition	No
Adjustable position feedback signal	No
Auxiliary contacts	No
Position reporting system	Optional
Auxiliary contacts optional	Yes
End contacts	None
Adjustable operating range	No
With mechanical setting indicator	Yes
Suitable for manual operation	Yes
Operating time	150 s
Torque	20 Nm
Potential free switch contact	No
Self-adjusting travel length	No
Max. angle of rotation	95 °
With safety function	No
Degree of protection (NEMA)	2
Degree of protection (IP)	IP54
Max. electric power input	4 VA
Ambient temperature (min)	-30 °C
Ambient temperature (max)	50 °C
Height	85 mm
Width	110 mm
Depth	220 mm
Explosion-proof	No
Housing material	Plastic
Suitable for valve	No