The AME 655-1, 658 SU/SD-1 and 685-1 series of motor actuators are suitable in providing valve control to the demands of district heating/ cooling, heating, ventilation, and air conditioning applications. The AME658 series of actuator provides safety function in either open or closing of the valve in the event of power loss. For the AME 655-1 and AME 685-1 this feature is not included. The actuators can be wired in either a modulating or floating control dependent on the requirements of the electronic controller’s output. The motor actuators AME 65x are assembled with the AB-QM series of pressure independent control valve for the sizes ranging from 5” (DN 125) to 6” (DN 150). The motor actuators AME 685-1x are assembled with the AB-QM series of pressure independent control valve for the sizes ranging from 8” (DN 200) to 10” (DN 250).