NM24-PWM US | Damper Actuator | 90 in-lb | Non-Spg Rtn | 24V | Modulating | Belimo (OBSOLETE)

Damper Actuator | 90 in-lb | Non-Spg Rtn | 24V | Modulating

Application/Operation

For control of dampers in HVAC systems. Actuator sizing should be done in accordance with the damper manufacturer’s specifications. The actuator mounts directly to a damper shaft with a universal V-bolt clamp assembly. The supplied antirotation bracket will prevent lateral movement of the actuator. The actuator is protected against overloading, and does not require limit switches. The angle of rotation is mechanically limited to 95°. When reaching the damper or actuator end position, the motor stops automatically. A spring-loaded button on the actuator cover allows the gears to be manually disengaged and the damper blades adjusted by hand. The position of the actuator is indicated by a visual pointer. Auxiliary switches are fastened to the actuator body for signaling and switching functions

NM24 US control is on-off from an auxiliary contact of a fan motor contactor, or a manual switch, with the direction of rotation reversible, for use with a floating point type control. The NM24- SR US operates in response to a 2 to 10 VDC control input from an electronic controller or positioner, or 4 to 20 mA with the addition of a 500Ω resistor. The NM24-PWM US actuator is controled with a pluse width modulating positioning signal. The signal range is externally selectable in four ranges. The NM24- SRS US is designed to work with input signals in the range of 0 to 29 VDC from an electronic controller or positioner. Two potentiometers to adjust the starting point and working span of the actuator allow for non-standard control ranges or sequencing of multiple actuators from one control signal. The NM24-SR US, NM24-SRS US and NM24-PWM US have a built-in microprocessor that automatically tests for the amount of rotation required to modulate the damper fully closed to fully open. The actuator will self-adjust to a consistent running time of 150 sec., and rescale the input signal so the entire 8 volt control range is used to provide maximum resolution of the control system. The microprocessor will correct for compression of tight close-off gaskets with age, providing the actuator is not on its mechanical stops. A functional test of the actuator/damper assembly may be done by pressing down the manual override button, this will activate the actuator’s test mode and cycle the actuator fully open and closed. A 2 to 10 VDC feedback (U) is provided with full 8-volt output range proportional to the operational rotation of the damper. A digital rotation sensing circuit protects the actuator in a stall anywhere in its 95° working range without limit switches