The basic operation of the pumping system with variable speed is to keep the pressure constant, independent of the required flow, thanks to the frequency variator that is accelerating and decelerating the pump in response to different water demands so that the outlet pressure is always the same . The pumps work only part of the time at their nominal speed (regulated according to consumption), thus achieving considerable energy savings, so that when the water consumption is zero the system stops, resuming its operation at variable speed when the power is restored. consumption, according to the power required for that point of operation.