Fan Coil Controller

The GRFCU-PR57-KNX device is a DIN rail EIB / KNX interface for fan coil units control. The device has 3 0-10 V outputs and 3×16 A relays. Two 0-10 V outputs are dedicated to the management of proportional valves, variable speed management be done with the third 0-10 V output or with the 3 relays on board.
If relays are not used for speeds, they can activate lights or other loads. An input is also available for reading 0-10V or 4-20mA signals to interface external probes for temperature, humidity, CO2 , etc; the third 0-10 V output can also be configured in this mode, as input. There are also 5 digital inputs for dry contacts in order to connect buttons, window contacts, alarms; 2 inputs can be connected to NTC temperature probes (codes GRTE-SEN and GRTE-SEN-2).
The logic inside the device can manage a 2/4 pipes fan coil with an internal 2-stage PI algorithm. A sophisticated parameterization allows its use in modern systems that require a differentiation of the behavior between speed and valves (independent regulation differentials), ventilation to avoid air stratification, logics for efficient maintenance of comfort and energy saving.