A floating pump can meet the needs of a wide variety of applications. These include fire pumping, marine service, environmental clean up, and irrigation.
A float switch moves up and down with the water level, closing or opening an electrical contact that turns on the pump. Using a properly sized drive pipe is important. If the drive pipe is too short the pressure wave created by the pump cannot develop properly and damage may result.
Float Switches
Float switches are fairly simple pieces of equipment that act as sensors for water. They have a hollow body that floats on the top of liquid tanks & contain internal switches with one or more magnets inside. When the float comes close to the magnet it opens the switch allowing an electrical current to flow through.
Most float switches are configured as “normally open” which means the contact is off when in the down position & closes in the up position. However, there are also float switches that are “down closed” meaning the contact is on when down. These are typically used in demand-dose systems.
Newer float switches, often called water level controls, use stainless steel probes instead of magnets. They are narrow-angle, which means that the liquid levels have to change by only a few inches for them to be activated or deactivated. They are often paired with tank alarms and pump controllers to perform multiple functions.
Internal Switches
A float switch works by having a hollow floating body that holds an internal mechanical switch. This switch can open or close an electrical circuit, which is used to trigger a pump. This type of switch is also called a sensor and can be made with many different materials.
When the float is activated, it rises to a pre-set level. Then, the switch is flipped and power is transferred to the pump, turning it on. As the float drops, the switch is again flipped and power is cut to the pump.
This type of switch is used with sump pits and other water or sewage applications. There are also tether float switches which feature a tether attached to the float and are often used with larger basins or sewage pumps. These tethers can also be adjusted for a wider range of trigger levels. This is done by increasing the tether length or decreasing it. This will affect the distance from which the float needs to reach to activate the switch.
Piggy-Back Plugs
Put your water pump, sewage system or grinder pump on autopilot with this cable-mounted float switch. It responds to the rise and fall of water levels in a tank, activating or deactivating the motor based on its position. This mechanical float switch is built to withstand prolonged exposure to harsh conditions.
A molded NEMA 5-15P series piggy-back plug is attached to the back of this float switch cord and allows you to plug in your pump into it. Connect the green wire from your pump to the ground terminal on the plug and the black or white free lead from your pump to one of the hot terminals on the switch.
Piggy-back plugs are an efficient way to utilize your power usage at home. They’re available in different lengths and gauges for your specific needs. They’re also UL/CSA approved for indoor and outdoor use. If you’re interested in purchasing a piggy-back plug, call us for more information.
Hard Wiring
Using a traditional cable suspended float switch to control a pump is not very convenient and can often be difficult to troubleshoot. It requires a lot of wires tied to some type of conduit and isn’t that reliable – most maintenance technicians expect these switches to fail within two or three years in service.
Adding an internal float switch to your existing pump is an inexpensive way to upgrade its performance. The Kari Float Switch is an excellent solution as it has built-in hysteresis and handles the logic, eliminating the need for additional wiring. It can also be used with a tank alarm or control panel to perform other functions.
When you purchase a float switch for your water system, make sure to take the time to measure your discharge pipe length and install the pump properly in a permanent weather-proof location. When working with electricity, always shut off the power supply before grabbing a wire! It is also important to label your wires for easy identification. Match the colors of the wires to their respective terminals on the motor leads.floating pumps for water