With the modulating feed water system, the level in the boiler is continuously adjusted by a PID regulator that, through an inverter positioned in the control board or on the pumps, control the water feeding pumps speed variation.

The water level in the generator is continuously detected by a capacitive probe, inserted in a calm barrel. The 4-20mA analog signal is transmitted to the electrical panel where an electronic controller elaborates the signal in Proportional Integral Derivative.

Using the thresholds suitably set up the controller provides the on/off output for the automatic starting and stopping of the supply pumps and an analog signal 0-10V for the inverter regulation.