If the water demand decreses, 4HS will reduce the speed (proportional to the frequency) to maintain constant pressure. As you can see from the chart, a speed reduction corresponds a significant decrease of the power consumption. For example, maintaining constant the 6 bar (197 psi), if speed drops from 4800 rpm to 4200 rpm, input power decreases from 1600W to 700W.
4HS can be used at a fixed speed by setting the operational frequency. To each frequency curve corresponds a different hydraulic performance and power consumption. This means that each 4HS model covers the performance offered by several standard pumps at fixed speed.
Among the parameters to be set in the CM control module, particularly useful is the possibility of limiting the maximum current absorbed by the pump. If this threshold is exceeded, for example in the even of a drop in input voltage, the control will reduce the 4HS pump speed to always ensure its operation.