Sump Pump

Overview

The Sump Pump keeps a basement pit dry. It sits at the bottom of the sump and runs automatically: as groundwater seeps in and the level rises, a float starts the pump, which throws the water up a riser pipe and out of the building. When the pit drains, the float drops and the pump stops. The Submersible Motor and Pump End are stacked into one submersible unit, switched by the Float Switch and sealed against the water it sits in.

How it works

The drive is the Submersible Motor, an oil-filled sealed induction motor. Filling the can with Motor Cooling Oil cools the windings and lubricates the bearings while keeping water out; an Oil Seal at the shaft and a Thermal Overload cutout guard against leaks and overheating. Single-phase starting torque comes from the Run Capacitor housed in the Control Box.

The motor shaft drives the Pump End. A thermoplastic vortex impeller spins inside the Volute Housing and slings water outward by centrifugal force, raising pressure at the rim and pushing flow into the Discharge Assembly. The vortex design keeps the impeller clear of the flow path so the pump can pass small solids without clogging. An Intake Screen blocks larger debris.

The Float Switch sets the run band. A sealed buoyant float on a tether rises with the water and tips an internal microswitch closed at the high level, then opens it again once the pit empties. Adjusting the tether length sets how high the water climbs before the pump fires and how low it pulls the pit down.

On the discharge, a spring Check Valve stops the column of water in the riser from draining back into the pit when the motor stops, which would otherwise refill the sump and cause needless restarts. The Standing Base raises the intake off the pit floor so silt is not drawn straight into the screen, and a molded Carry Handle lets you lift the unit for service.