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Many submersible pumps are float switch activated. It’s important to choose a float switch that’s correctly sized and configured for your application as the right switch can extend a pump’s life and the wrong one can cause a pump to prematurely burn out or malfunction.

Float switches are available in tethered, vertical and diaphragm designs. Each type has benefits and drawbacks. Choosing the float switch that’s right for you depends on your budget, the amount of time are you are willing to spend monitoring a pump and your tolerance for pump malfunction.

PHCC Pro Series Float Switch Options

 Tethered Float Switch

A tethered float switch consists of a cord and a float that moves up and down on the water’s surface and turns the pump on and off as the water level rises and falls.

Tethered floats are among the simplest and least expensive switches and are commonly used in large diameter, deep pit sump and sewage applications. Tethered floats allow the pump to be off longer between pump cycles, which allows the motor to cool more completely. This can extend the life of a pump and lower usage costs.

Tethered floats are available in mechanically activated and mercury activated designs and in “pump up” and “pump down” styles. A pump down switch will turn on the electricity when the float is in the up position. A pump up switch will turn on the electricity when the float is in the down position.

Tethered floats often have a “piggyback plug” to facilitate installation and operation.  However, they require frequent checks. In addition to burning out and getting caught in sump pit debris, tether floats can get pinned against the wall of a well or sump pit when vibration causes a pump to drift.

Vertical Float Switch

A vertical float switch consists of a float attached to a pole that is vertically placed inside the sump pit. As the float moves up and down along the pole, it turns the pump on and off.

Vertical float switches are ideal for narrow sump basins. They tend to run a pump more often than tethered floats and prevent pit water from getting too deep.

They require frequent checking as they are prone to the same obstructions as tether floats.

Diaphragm Switch

Diaphragm switches contain a membrane that is convex when the water is at low levels, and concave when the water rises.  The concave membrane kicks in the pump. When the water level falls the membrane moves back to its convex shape and disengages the pump. These switches rely on changes in water pressure and are ideal for use with submersible well pumps and applications where space is limited.

Diaphragm switches require less monitoring than float switches as they are less mobile. They are, however, subject to obstruction by small pebbles and loss of flexibility in the activating membrane.

PumpProduct.com application engineers are standing by to provide technical assistance, price quotes or to answer any questions you may have regarding float switches by leading manufacturers including Goulds, Zoeller and Little Giant.  Call our Toll Free Number 1-800-429-0800.