Float Switches

Industries that work with liquids need a way to monitor their levels in the container. Float switches continue to be a reliable method of level monitoring after centuries of use in one form or another.

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What Is a Float Switch?

A float switch is a sensor that monitors the tank circuit and activates a pump control panel or alarm through an electric circuit to control a liquid level. The switch raises and lowers with the increased or decreased liquid level and is used in an electrical circuit.

The float switch has many components:

  • Hollow body: Also called the float, it has a built-in magnet.
  • Guide tube: This tube guides the float.
  • Adjusting collars: The collars limit the distance the float can travel in the tube.
  • Reed contact: This contact is on the inside of the float.


The water level controls the angle of the float switch, which determines the magnet’s position. If the magnet is close to the reed switch, it creates a closed circuit where the electric current can flow. If it moves away, the circuit is open and allows no flow. As the float switch raises with the water, the magnet moves closer to the reed contact for a closed circuit. As the switch lowers with the water, the magnet moves away from the reed contact for an open circuit.

Uses for Float Switches

Float switches are used in industrial processes that need to monitor liquid levels, as they can prevent the liquid from getting too high or low. Some applications include:

  • Beverages: The beverage industry relies on float switches to keep track of the liquid in beverage tanks.
  • Water tanks: Float switches can monitor water levels for sewage, wastewater, potable water and rainwater.
  • Sump pumps: Float switches in a sump pump will activate the pump to prevent the water from reaching the top of the pit.
  • Refrigerant and A/C: The refrigerant and A/C industries use float switches to control water levels.


Common Problems and Questions About Float Switches

There are a couple of standard float switch types available that are installed in different ways, yet achieve the same goal of monitoring liquid levels.

One of these types is a vertical float, which is attached to the top or bottom of the tank. A horizontal float is used when the tank lid is closed or out of reach. When the float is close to a reed switch, the magnetism will open or close the circuit for both vertical and horizontal installation.

Buy Float Switches at Global Electronic Services Today

Global Electronic Services is the industry’s leader for industrial electronic sales and repairs. We have thousands of new, surplus, used and obsolete units for sale on our website, and we also offer a maintenance service with a one to five day turnaround time.

Global Electronic Services has many float switch options — browse the options on this page to see what we have. Place your order today on our website or learn more about our products by calling 877-249-1701.

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