Frequency inverters

A variable frequency drive changes the pump speed so the pressure in the house stays the same with one tap open or three. The pump starts gently, without water hammer, and at low demand it runs slower and uses less electricity.

The drive is chosen by motor current and supply type. With one, a small 2–8 L pressure tank is enough. If your pump keeps switching on and off, the causes are covered in “Why a pump short-cycles”.