Technical Data

1446

Power Supply

24 VAC, ±20%, 50/60 Hz, 24 VDC, 0% /

+50%

Power consumption in operation 27 VA

Power consumption in rest

position

3 W, 6.5 VA, End stop 55 VA, 2.5 A slow

blow fuse *

Transformer sizing

40 VA (class 2 power source)

Shaft Diameter

1/2...1.05” round, centers on 1/2” and 3/4”

with insert, 1.05” without insert

Electrical Connection

18 GA, 3 ft [1 m], 2 color coded wires

Overload Protection

electronic throughout 0...95° rotation

Electrical Protection

actuators are double insulated

Angle of rotation

95°

Torque motor

70 in-lb [8 Nm] from 32...350°F [0...177°C]

Direction of motion motor

selectable by ccw/cw mounting

Direction of motion fail-safe

reversible with cw/ccw mounting

Position indication

Mechanical

Running Time (Motor)

15 s between 32...350°F [0...177°C], <15 s

at rated voltage & torque

Running time fail-safe

15 s

Ambient humidity

max. 95% r.H., non-condensing

Ambient temperature

32...122°F [0...50°C]

Storage temperature

-40...176°F [-40...80°C]

Degree of Protection

IP40, NEMA 1

Housing material

galvanized steel

Gears

steel, permanently lubricated

Agency Listing

cULus listed to UL873 and CAN/CSA C22.2

No.24, UL 2043 Listed for air plenum

installation per NEC 300.22 and IMC Section

602

NYC Department of Buildings MEA 197-

07-M.California State Fire Marshal Listing

3210-1593:101.

Noise level, motor

45 dB(A)

Noise level, fail-safe

62 dB(A)

Servicing

maintenance-free

Quality Standard

ISO 9001

Weight

5.7 lb [2.8 kg]

† UL File XAPX.E108966

Fire & Smoke damper actuator

Application

The type FSNF spring-return actuator is intended for the operation of smoke

and combination fire and smoke dampers in ventilation and air-conditioning

systems. The actuator will meet requirements of UL555 and UL555S when

tested as an assembly with the damper and will meet requirements of UBC for

15 second opening and closing at 350°F. Square footage of damper operated

will depend on make and model and the temperature required.

IMPORTANT 24VDC NOTE: The FSNF24 & -S models will not operate below

24VDC. A filtered and regulated power supply must be used.

Operation

Mounting of the actuator to the damper axle shaft or jackshaft (3/8” to 1.05”) is

via a cold-weld clamp. Teeth in the clamp and V-bolt dig into the metal of both

solid and hollow shafts maintaining a perfect connection. The specially designed

clamp will not crush hollow shafts. The bottom end of the actuator is held by an

anti-rotation strap or by a stud provided by the damper manufacturer.

The actuator is mounted in its fail safe position with the damper blade(s) closed.

Upon applying power, the actuator drives the damper to the open position. The

internal spring is tensioned at the same time. If the power supply is interrupted,

the spring moves the damper back to its fail-safe position.

Dimensions (Inches[mm])

Standard:

1/2" to 1.05"

Optional*

3/8" to 3/4"

*with K4 US clamp

1.97"

[50]

2.64"

[67]

0.26" [6.5]

5.85" [148.5]

10.20" [259]

0.35" [9]

0.39" [10]

0.65" [16.5]

0.19" [5]

[ø41.2]

ø1.62"

[191.6]

7.54"

Safety Notes

* Neither UL nor Belimo require local over-current protection. The FSNF

actuators draw higher peak current when driving against any type of stop. If

used, this requires the value of a local fuse or breaker to be increased to avoid

nuisance opening or tripping. A 2.5 A slow blow should be used for AC 24 V.

A 0.5 A slow blow should be used for AC 120 V. A 0.25 A slow blow should be

used for 230 V and a 0.3 A slow blow for AC 208 V. Transformers: Note that

while a 24 V 100 VA transformer would handle 2 actuators, a 4 A breaker or

plug fuse is insufficient. A 5 A slow blow would be required.

Belimo Fire & Smoke actuators have passed the AMCA 520 and UL 555S Long

Term Holding test. No special cycling is required during prolonged periods

when actuator is driven open and held there. Periodic testing of dampers and

actuators per local codes and NFPA 80 and NFPA 105 are required.

The actuator contains no components which the user can replace or repair.

A 1/2” threaded connector is standard. FSNFxx-FC models have a 3/8” Flex

Connector. Other than the connector, these actuators are identical to the

conduit connector version.

FSNF24 US Technical Data Sheet

On/Off, Spring Return, 350°F [177°C] for half an hour, 15 s Cycle Time

800-543-9038 USA

866-805-7089 CANADA

203-791-8396 LATIN AMERICA / CARIBBEAN