Little Giant Tethered Float Switch 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, diaphragm and electronic designs. Each type has benefits and drawbacks. Choosing the float switch that's right for you depends on your budget, the amount 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.

Electronic Pump Switch

Electronic switches consist of a control module and a sensor that is set at a level at which the pump is to be activated. When water rises to the sensor, the pump kicks in and pumps down the water.

Electronic switches are not subject to obstruction like float switches or aging like diaphragm switches and are among the most reliable switch types available. They can be programmed with high water and low water shut-offs to maximize pump cycle time and minimize the chance of burn out in low water conditions. Many models will sound an alarm when there is a problem.  Electronic pump switches are ideal for  areas where the water table is high and it is impractical to empty the pit during every cycle.

Electronic switches are not suitable for use in pits that gather water from laundry or wash sinks as coating with detergents can cause them to malfunction.

Pump Product 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 Zoeller, Liberty, Little Giant and PHCC Pro Series.  Call our Toll Free Number 1-800-429-0800.