Technical Data

1379

Power Supply

24 VAC, ±20%, 50/60 Hz, 24 VDC, -10% /

+20%

Power consumption in operation 6 W

Power consumption in rest

position

2.5 W

Transformer sizing

8.5 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 appliance cable, 3 ft [1 m], with 1/2”

conduit connector

Overload Protection

electronic throughout 0...95° rotation

Electrical Protection

actuators are double insulated

Angle of rotation

95°, adjustable with mechanical end stop,

35...95°

Torque motor

90 in-lb [10 Nm]

Direction of motion motor

selectable by ccw/cw mounting

Direction of motion fail-safe

reversible with cw/ccw mounting

Position indication

Mechanical

Manual override

5 mm hex crank (3/16” Allen), supplied

Running Time (Motor)

75 s

Running time fail-safe

<20 s @ -4...122°F [-20...50°C], <60 s @

-22°F [-30°C]

Ambient humidity

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

Ambient temperature

-22...122°F [-30...50°C]

Storage temperature

-40...176°F [-40...80°C]

Degree of Protection

IP54, NEMA 2, UL Enclosure Type 2

Housing material

Galvanized steel and plastic housing

Agency Listing

cULus acc. to UL60730-1A/-2-14, CAN/CSA

E60730-1:02, CE acc. to 2014/30/EU

Noise level, motor

50 dB(A)

Noise level, fail-safe

62 dB(A)

Servicing

maintenance-free

Quality Standard

ISO 9001

Weight

4.9 lb [2.2 kg]

†Rated Impulse Voltage 800V, Type of action 1.AA, Control Pollution Degree 3

Torque min. 90 in-lb, for control of air dampers.

Application

For On/Off, fail-safe control of dampers in HVAC systems. Actuator sizing

should be done in accordance with the damper manufacturer’s specifications.

Control is On/Off from an auxiliary contact or a manual switch. The actuator

is mounted directly to a damper shaft up to 1.05” in diameter by means of its

universal clamp. A crank arm and several mounting brackets are available for

applications where the actuator cannot be direct coupled to the damper shaft.

Operation

The NF..24 series actuators provide true spring return operation for reliable

failsafe application and positive close off on air tight dampers. The spring

return system provides constant torque to the damper with, and without,

power applied to the actuator. The NF..24 series provides 95° of rotation and is

provided with a graduated position indicator showing 0° to 95°. The actuator

may be stalled anywhere in its normal rotation without the need of mechanical

end switches. The NF..24 actuator is shipped at 5° (5° from full fail-safe) to

provide automatic compression against damper gaskets for tight shut-off.

Dimensions (Inches[mm])

2.31" [58.78]

5.32" [135.01]

1.25" [31.79]

6.77" [172]

0.38" [9.7]

0.26" [6.5]

0.8" [20.38]

0.26" [6.5]

9.69" [246.1]

NFB24 Technical Data Sheet

On/Off, Spring Return, AC/DC 24 V

800-543-9038 USA

866-805-7089 CANADA

203-791-8396 LATIN AMERICA / CARIBBEAN