Patent ID: 8727737

Claim:
A submersible pump system comprising: a pressure switch configured to measure a surface pressure of a fluid in piping proximate to a use point of the fluid in the piping; a power source having a power line extending therefrom, the power source configured to shut off power to the pump when a maximum pressure condition is detected at the pressure switch; a submersible pump assembly having one or more stages of impellers, the pump assembly having a discharge fitting configured to be connected to the piping; a pressure sensor measuring a pressure of fluid directed through the discharge fitting into the piping, the pressure sensor being positioned above the discharge fitting in proximity to the submersible pump assembly and remote from the pressure switch, the pressure at the pressure sensor being greater than the surface pressure; and a submersible motor assembly driving the pump assembly, the motor assembly having a motor housing, a motor within the motor housing for driving the pump assembly and a control module for operating the motor, the control module being electrically connected to the power line, the control module being electrically connected to the pressure sensor by a sensor cable entirely submerged with the submersible pump assembly and submersible motor assembly, the control module comprising a controller and a variable frequency drive driven by the controller based on pressure data from both the pressure switch and the pressure sensor; wherein the controller is calibrated by measuring the pressure sensed by the pressure sensor at a time when the power source is shut off when the maximum pressure condition is detected by the pressure switch; and wherein the controller operates the variable frequency drive to drive the motor to maintain a constant pressure output condition from the pump assembly at a pressure that is a fraction of the measured pressure sensed at the time when the power source is shut off when the maximum pressure condition is detected by the pressure switch.