How Does a Float Switch Work?

FFloat switches detect the level of liquid in a tank or container. A float switch works by floating on the surface of the liquid and activating a switch as the liquid level rises or falls. They are used to control equipment such as pumps, alarms, or valves and can be used with many different liquids.

How a Float Switch Works

The float switch moves vertically as the liquid level rises and falls. It utilizes a counterweight and trigger to open and close the connected device. Usually, the connected device stops or starts liquid flowing into the container. The switch is constructed from a hollow floating body and an internal switch or water level sensor. The most common type is a reed switch, which contains a magnet. There are other types of switches, but they all work by using gravity and the water level to move the float. 

What a Float Switch Can Be Used For

Float switches are used in applications where a pump, valve, or alarm needs to be switched on or off based on the level of water in a container. Sump pumps use these switches to detect the amount of water in the sump pit and switch the pump on and off accordingly. These switches are often used in water tanks, such as toilet tanks, to control the water level of rainwater, wastewater, potable water, or sewage. Air conditioning and refrigerant systems and industrial washers often use these switches to control water levels. They are also used by the beverage industry to empty or fill beverage tanks.

Float switches are a relatively simple device that has a wide range of applications and is fairly easy to install and maintain. These switches are invaluable for applications that rely on automatically controlling devices based on the level of a liquid in a tank or other container.