Belimo AF24-SR US Fail-Safe Proportional Damper Actuator (QT:8)

Description

Belimo AF24-SR US Fail-Safe Proportional Damper Actuator (QT:8).
The actuator is mounted directly to a damper shaft up to 1.05”in diameter by means of its universal clamp. A crankarm andseveral mounting brackets are available for applications wherethe actuator cannot be direct coupled to the damper shaft.The actuator operates in response to a 2 to 10 VDC, with theaddition of a 500Ω resistor, a 4 to 20 mA control input from anelectronic controller or positioner. A 2 to 10 VDC feedbacksignal is provided for position indication or master-slave applications.
The AF series actuators provide true spring return operation forreliable fail-safe application and positive close-off on air tightdampers. The spring return system provides constant torque tothe damper with, and without, power applied to the actuator.The AF series provides 95° of rotation and is provided with agraduated position indicator showing 0 to 95°. The AF has aunique manual positioning mechanism which allows the setting of any damper position within its 95° of rotation. Theactuator is shipped at +5° position (5° from full fail-safe) toprovide automatic compression against damper gaskets fortight shut-off. When power is applied, the manual mechanismis released and the actuator drives toward the full fail-safeposition. The actuator will memorize the angle where it stopsrotating and use this point for its zero position for its normalcontrol operations. The manual override can also be releasedphysically by the use of a crank supplied with the actuator.The AF uses a brushless DC motor which is controlled by anApplication Specific Integrated Circuit (ASIC) and a microprocessor. The microprocessor provides the intelligence to theASIC to provide a constant rotation rate and to know the actuator’s exact zero position. The ASIC monitors and controlsthe brushless DC motor’s rotation and provides a digital rotation sensing function to prevent damage to the actuator in astall condition. The actuator may be stalled anywhere in itsnormal rotation without the need of mechanical end switches.