Belimo NFA-S2 Spring Return Damper Actuator (10Nm, Multi-Voltage, Open/Close, 2x Aux)

Immediately available

Belimo NFA-S2 Spring Return Damper Actuator (10Nm, Multi-Voltage, Open/Close, 2x Aux)

Immediately available

Brand: Belimo

Product type: Valve Actuator

Operating Voltage: AC 24...240 V / DC 24...125 V

Force / Torque: 10 Nm

Control Signal: 2 Position

Belimo NFA-S2 fail-safe spring return rotary actuator for HVAC dampers up to approx. 2 m²; AC 24–240 V / DC 24–125 V, open/close, 10 Nm, IP54 / NEMA 2, 75 s/90°, with 2x SPDT auxiliary switches.

Product information "Belimo NFA-S2 Spring Return Damper Actuator (10Nm, Multi-Voltage, Open/Close, 2x Aux)"

The Belimo NFA-S2 is a robust fail-safe spring return actuator engineered to drive HVAC dampers to a defined safety position on power loss. It uses a universal power supply module accepting AC 24…240 V and DC 24…125 V, simplifying site standardization across projects.

During normal operation, the actuator moves the damper to the operating position while tensioning the spring. When the supply is interrupted, the spring automatically returns the damper to the fail-safe position. It includes a hand-crank manual override with locking switch for commissioning and service, and two integrated auxiliary switches for end-position signalling and interlocks.

Applications

AHU and duct air dampers requiring fail-safe return
Outside air / exhaust / shut-off dampers where safety position is required
BMS interlocks (fan enable, damper proof, alarms) using aux switches
Sites needing multi-voltage standardization (one actuator for many supply types)

Technical data

Specification	Value
Model	NFA-S2
Damper size	Up to approx. 2 m²
Supply voltage	AC 24…240 V / DC 24…125 V
Voltage range	AC 19.2…264 V / DC 21.6…137.5 V
Frequency	50/60 Hz
Control	Open/Close (On/Off)
Torque (motor)	10 Nm
Torque (fail-safe)	10 Nm
Running time (motor)	75 s / 90°
Fail-safe time	<20 s @ -20…50°C; <60 s @ -30°C
Rotation angle	Max 95° (adjustable from 33% in 2.5% steps)
Power consumption	6 W (op); 2.5 W (rest); 9.5 VA (wire sizing)
Auxiliary switches	2x SPDT (1x 10% fixed / 1x 11–100% adjustable)
Aux switch rating	1 mA…3 A (0.5 A inductive), DC 5 V…AC 250 V
Protection	IP54; NEMA 2; UL Enclosure Type 2
Manual override	Hand crank + locking switch
Shaft clamp	Universal 10…25.4 mm
Sound level	45 dB(A)
Service life	Min. 60,000 fail-safe positions
Ambient	-30…50°C; max 95% RH non-condensing
Storage	-40…80°C
Weight	2.2 kg
Hygiene test	VDI 6022 Part 1 / SWKI VA 104-01
UL approval	cULus (UL60730-1A, UL60730-2-14)