Fire & Smoke Actuator, 180 in-lb [20 Nm], Spring return, AC/DC 24 V, 2…10 V, 2 x SPDT

Fail-safe position

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Weight 5.0 lbs
Auxiliary Switch




Actuator Type

Spring return

maintenance free
Torque motor
[20 Nm]
20 Nm
Power consumption in operation
6 W, 9.5 VA
Power consumption in rest position
3 W, 5 VA
Transformer sizing
10 VA (class 2 power source 24 VAC only)
Ambient humidity
5...95% r.H. non-condensing
Housing material
zinc coated metal and plastic casing
Electrical Connection
(2) 18 GA appliance cables with 1/2" conduit connectors, 3 ft [1 m],
Auxiliary switch
2 x SPDT, 3A resistive (0.5A inductive) @ 250 VAC, one set at 10°, one adjustable 10...90°
Switching capacity auxiliary switch
3A resistive (0.5A inductive) @ 250 VAC
Auxiliary switch note
one set at 10°, one adjustable 10...90°
Manual override
5 mm hex crank (3/16" Allen), supplied
Angle of rotation
95°, adjustable with mechanical end stop, 35...95°
Noise level, motor
inaudible holding, running <40 dB (A) spring <62 dB (A) 
Position indication
visual indicator, 0° to 95° (0° is full spring return position)
Ambient temperature
-22...122°F [-30...50°C]
Non-operating temperature
-40...176°F [-40...80°C]
Operating range Y
DC 2...10 V
Control operating range Y note
4...20 mA w/ ZG-R01 (500 Ω, 1/4 W resistor)
Position feedback U
DC 2...10 V
Position feedback U note
Max. 0.5 mA
Position Feedback
DC 2...10 V, Max. 0.5 mA
direction of rotation spring-return
reversible with cw/ccw mounting
For proportional control of fire and smoke combination and smoke dampers in UL555S applications. In new installations, UL 555S requires that actuators be mounted by the damper manufacturer.
Overload Protection
electronic throughout 0° to 95° rotation
Electrical Protection
actuators are double insulated
Input Impedance
100 kΩ for DC 2...10 V (0.1 mA), 500 Ω for 4...20 mA
Quality Standard
ISO 9001
Operating Range
DC 2...10 V, 4...20 mA w/ ZG-R01 (500 Ω, 1/4 W resistor)
Degree of Protection
IP54, NEMA 2, UL Enclosure Type 2
Agency Listing
CE, UL 60730-1, CSA C22.2 No. 139 certified Listed to UL 2043 - suitable for use in air plenums per Section 300.22(C) of the NEC and Section 602 of the IMC
steel, permanently lubricated
direction of rotation motor
reversible with CW/CCW mounting
Data sheet type
CAD ThomasNetLink
Product Features
Torque min. 180 in-lb, Control 2 to 10 VDC, Feedback 2 to 10 VDC
Nominal voltage
AC/DC 24 V
Nominal voltage AC
24 V
Nominal voltage DC
24 V
Nominal voltage frequency
50/60 Hz
Power Supply
24 VAC, ±20%, 50/60 Hz, 24 VDC, -10% / +20%
Power supply tolerance AC
Power supply tolerance DC
-10% / +20%
Mechanical accessories
Electrical accessories
Family Series
FSAF Series
Shaft Diameter
1/2" to 1.05" round, centers on 1/2" and 3/4" with insert, 1.05" without insert
Running time selection
50...79 sec
Running Time (Motor)
75 sec
Running time (Fail-Safe)
<20 seconds
Running Time (Fail-Safe)
<20 sec
Emergency control function
Spring Return
VA Rating
Angle of rotation note
adjustable with mechanical end stop, 35...95°
Degree of protection IEC/EN
Degree of protection NEMA/UL
UL Enclosure Type 2
Not purchasable function
Tagging function
Auxiliary Switch
The FSAFB24-SR & FSAFB24-SR-S actuators provide 95° of rotation and are provided with a graduated position indicator showing 0° to 95°. A unique manual override allows the setting of any actuator position within its 95° of rotation with no power applied. This mechanism can be released physically by the use of a crank supplied with the actuator. When power is applied the manual override is released and the actuator drives toward the fail-safe position to synchronize before going to the position commanded by the signal. The actuator uses a brushless DC motor which is controlled by an Application Specific Integrated Circuit (ASIC).The ASIC monitors and controls the brushless DC motor’s rotation and provides a Digital Rotation Sensing (DRS) function to prevent damage to the actuator in a stall condition. The position feedback signal is generated by a feedback potentiometer. The actuator may be stalled anywhere in its normal rotation without the need of mechanical end switches. The actuator cannot burn out from being stalled before full rotation is achieved. The FSAFB24-SR, FSAFB24-SR-S, is mounted directly to control shafts up to 1.05” diameter by means of its universal clamp and anti-rotation bracket. A crank arm and several mounting brackets are available for damper applications where the actuator cannot be direct coupled to the damper shaft. The spring return system provides the specified torque to the application during a power interruption. The FSAFB24-SR, FSAFB24-SR-S, actuator is shipped at +5° (5° from full fail-safe) to provide automatic compression against damper gaskets for tight shut-off.
CP65 Warning
⚠ WARNING: For Belimo Products sold in California, these Products do or may contain chemicals which are known to the State of California to cause cancer and or birth defects or other reproductive harms. For more information see www.p65warnings.ca.gov.

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