Float Switches

Usually associated with pumping systems, float switches are used to start and stop pumps as a function of reservoir or tank levels. Their design allows them to control either high level (to start the 'emptying' pumps) or low level (to start the 'filling' pumps). The choice of the individual switch will depend upon such factors as reservoir or tank dimensions, the nature of liquids involved, their temperature, and the operating environment. A float switch comprises a dust and damp protecting enclosure containing the contact blocks and an operating lever pivoted in the centre. There is a counterweight and cable suspended from one side of the lever and a float and cable, or rod, from the other. The switch operates by the pivoting of this lever, which is related to the liquid level.