800-543-9038
USA
866-805-7089
CANADA
203-791-8396
LATIN AMERICA
24
Torque min. 133 in-lb, for control of air dampers
Application
For proportional modulation of dampers in HVAC systems. Actuator sizing should
be done in accordance with the damper manufacturer’s specifications.
The actuator is mounted directly to a damper shaft up to 1.05” in diameter by
means of its universal clamp. A crankarm and several mounting brackets are
available for applications where the actuator cannot be direct coupled to the
damper shaft.
The actuator operates in response to a 2 to 10 VDC, with the addition of a 500
7
resistor, a 4 to 20 mA control input from an electronic controller or positioner.
Operation
The AFA series actuators provide true spring return operation for reliable fail-safe
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 AFA series provides 95° of rotation and is provided with a graduated position
indicator showing 0 to 95°. The AFA has a unique manual positioning mechanism
which allows the setting of any damper position within its 95° of rotation. The
actuator is shipped at +5° position (5° from full fail-safe) to provide automatic
compression against damper gaskets for tight shut-off. When power is applied,
the manual mechanism is released and the actuator drives toward the full fail-
safe position. The actuator will memorize the angle where it stops rotating and
use this point for its zero position for its normal control operations. The manual
override can also be released physically by the use of a crank supplied with the
actuator.
The AFA uses a brushless DC motor which is controlled by an Application
Specific Integrated Circuit (ASIC) and a microprocessor. The microprocessor
provides the intelligence to the ASIC to provide a constant rotation rate and to
know the actuator’s exact zero position. The ASIC monitors and controls the
brushless DC motor’s rotation and provides a digital rotation sensing function to
prevent damage to the actuator in a stall condition. The actuator may be stalled
anywhere in its normal rotation without the need of mechanical end switches.
Dimensions
(Inches [mm])
1.97"
3.15" [80]
3.86" [98]
3.25" [82.7]
2.24"
[57]
[50]
1.93"
[49]
2.64"
[67]
0.26" [6.5]
5.85" [148.5]
10.47" [266]
0.35" [9]
0.39" [10]
0.65" [16.5]
0.19" [5]
K4-2 US
(supplied)
1/2" Centered
(Default)
3/4"
Centered
(Field
Selectable)
1.05"
Centered
(Field
Selectable)
K4-1 US
(optional)
3/4" to 1.05"
Adjustable
K4 US
(optional)
3/8" to 3/4"
Adjustable
D001
AFA24-SR US
Proportional Damper Actuator, Spring Return Fail-Safe 24V for 2 to 10 VDC and 4 to 20 mA Control Signal.
Technical Data
AFA24... US
Power supply
24 VAC ± 20% 50/60 Hz
24 VDC ± 10%
Power consumption
running 6 W
holding 2 W
Transformer sizing
10 VA (class 2 power source)
Electrical connection
3 ft, 18 GA appliance cable
1/2” conduit connector
Overload protection
electronic throughout 0 to 95° rotation
Operating range Y
2 to 10 VDC, 4 to 20 mA
Input impedance
100 k
7
(0.1 mA), 500
7
Angle of rotation
mechanically limited to 95°
Torque
133 in-lb [15 Nm] constant
Direction of rotation
spring reversible with cw/ccw mounting
motor reversible with built-in switch
Position indication
visual indicator, 0° to 95°
(0° is spring return position)
Manual override
3mm hex crank (shipped w/actuator)
Running time
150 sec. constant, independent of load,
spring return < 20 sec
Humidity
5 to 95% RH non-condensing
Ambient temperature
-22°F to 122°F [-30°C to 50°C]
Storage temperature
-40°F to 176°F [-40°C to 80°C]
Housing
NEMA type 2 / IP54
Housing material
zinc coated metal
Agency listings
cULus acc. to UL 873 and
CAN/CSA C22.2 No. 24-93
Noise level
max. 45 dB (A)
Servicing
maintenance free
Quality standard
ISO 9001
Weight
6.0 lbs (2.7 kg.)
K20901 - 01/09 - Subject to change. © Belimo Air
controls (USA), Inc.
