The new microcontroller based FKD331 is a multistage electronic capacity controller for multicylinder reciprocating compressor or rack systems. LCD Based unit has easy to use settings, like Set point -Low pressure (LP), Neutral Zone (NZ) & Interstage timer. One Analog input (4 to 20mA) for
pressure transmitter e.g. compressor suction or RTD Pt100 One Digital input (potential free) for Compressor On feedback Four / Six Relay Output for Compressor Capacity Control Solenoid Valves and Compressor trip Adjustable Neutral Zone, time delay, Calibration Optional RS232 / RS485 port for communication Optional available Software for PC monitoring Function Capacity regulation The cut-in capacity is controlled by signals from the connected
pressure transmitter and the set reference. Outside the reference a neutral zone is set where the capacity will neither be cut in nor out. Outside the neutral zone the capacity will be cut in or out if the regulation registers a will take place with the set time delays. If the pressure however 'approaches' the neutral zone, the controller will make no changes of the cut-in capacity. Cut-in of steps are defined for either sequential or cyclic operation.