SKU
SRFA-S2

SRFA-S2 Spring-return Actuator NC, 20 Nm, AC / DC 24...230 V - Belimo | ideal for ball valves

£409.08 £340.90
On request
Next Supplier Stock Update: 18/04/2026
Free delivery over £30
Manuals & Datasheets
 DATASHEET 
DATASHEET
 
Product typeActuator
IP ratingIP54
ManufacturerBelimo
Power Supply24Vac/Vdc
Torque20 Nm
Running time65 to 80 sec
End Switches2 End Switches
Fail SafeSpring Return
Ideal for butterfly valves, rotary valves

At IACS we provide Free Delivery and Next 1-2 day Delivery for all the Belimo Actuators in stock.

The Belimo SRFA-S2 is an Actuator used in HVAC applications and air ventilation systems.

The Torque force applied by the SRFA-S2 is 20 Nm.

The power supply requested for this Rotary Actuator is 24Vac/Vdc.

Find at IACS the ideal Belimo Actuator compatible with your system at the best price.

If you are unsure about size or installation, refer to the Belimo custom datasheet above or message iacs to receive special instructions and a custom quote.

SRFA-S2 Spring-return Actuator NC, 20 Nm, AC / DC 24...230 V

  • Spring-return actuator NC
  • 20 Nm, < 75 s, 90°
  • AC / DC 24...230 V, Open/Close, 2 x SPDT
  • IP 54, Manual override with integrated position stop
  • Running time spring < 20 s
  • Connection PVC cable 1m
  • Auxiliary switch 2 integral
  • Emergency control closed
  • with mounting kit for RKH mounted

Mode of operation: The actuator is equipped with a universal voltage feed module that can utilise supply voltages of AC 24 ... 240V and DC 24 ... 125V. The actuator moves the valve to the operating position at the same time as tensioning the return spring. The valve is turned back to the emergency position by spring force when the supply voltage is interrupted.

Direct mounting: Simple direct mounting on the ball valve with only one screw. The mounting orientation in relation to the ball valve can be selected in 90° steps.

Manual override: Manual actuation of the valve with manual elevator crank, engagement with the locking switch at any position. Unlocking is manual or automatic by applying the operating voltage.

High functional reliability: The actuator is overload protected, requires no limit switches and automatically stops when the end stop is reached.

Adjustable angle of rotation: Adjustable angle of rotation with mechanical end stop. Flexible signalization The actuator has one auxiliary switch with a fixed setting and one adjustable auxiliary switch. They permit a 10% or 11...90% angle of rotation to be signaled.

Electrical data:

  • Nominal voltage AC 24...240 V / DC 24...125 V
  • Nominal voltage frequency 50/60 Hz
  • Nominal voltage range AC 19.2...264 V / DC 21.6...137.5 V
  • Power consumption in operation 7 W
  • Power consumption in rest position 3.5 W
  • Power consumption for wire sizing 18 VA
  • Auxiliary switch 2 x SPDT, 1 x 10% / 1 x 11...90%
  • Switching capacity auxiliary switch 1 mA...3 (0.5) A, AC 250 V
  • Connection supply / control Cable 1 m, 2 x 0.75 mm²
  • Connection auxiliary switch Cable 1 m, 6 x 0.75 mm²
  • Parallel operation Yes (note the performance data)

Functional data:

  • Torque motor Min. 20 Nm
  • Torque spring return Min. 20 Nm
  • Direction of rotation spring-return Deenergised NC, valve closed (A - AB = 0%)
  • Manual override By means of hand crank and locking switch
  • Angle of rotation 90°
  • Running time motor 75 s / 90°
  • Running time emergency setting position < 20 s / 90°
  • Sound power level motor max. 45 dB(A)
  • Position indication Mechanical
  • Service life Min. 60,000 emergency positions

Safety:

  • Protection class IEC/EN II Protective insulated
  • Protection class UL II Protective insulated
  • Protection class auxiliary switch IEC/EN II Protective insulated
  • Degree of protection IEC/EN IP54
  • Degree of protection NEMA/UL NEMA 2, UL Enclosure Type 2
  • EMC CE according to 2004/108/EC
  • Low voltage directive CE according to 2006/95/EC
  • Certification IEC/EN IEC/EN 60730-1 and IEC/EN 60730-2-14
  • Certification UL cULus according to UL 60730-1A, UL 60730-2-14 and CAN/CSA E60730-1:02
  • Mode of operation Type 1.AA.B
  • Rated impulse voltage supply / control 4 kV
  • Rated impulse voltage auxiliary switch 2.5 kV
  • Control pollution degree 3
  • Ambient temperature -30...50°C
  • Non-operating temperature -40...80°C
  • Ambient humidity 95% r.h., non-condensing
  • Maintenance Maintenance-free

Weight: Approx. 2.5 kg