Patent ID: 8011895

Claim:
A method for a no water/dead head detection pump protection comprising: (1) receiving in a controller a feedback signal containing information about pressure produced by a pump and a signal containing information about motor speed and power consumption of the pump; (2) detecting in the controller that a no water/dead head condition exists by checking if three conditions are satisfied, including: (a) power consumption of the pump and motor is below full load, (b) the speed of the pump and motor is at full speed, and (c) the pressure of the pump is below a desired operating pressure set point; (3) if all three conditions are satisfied, then providing a control signal to lower the speed of the motor and pump, and turning off the pump and motor if the pressure produced by the pump does not drop; and (4) if either all three conditions (a), (b) and (c) are not satisfied, or the pressure produced by the pump drops when the speed of the motor and pump is lowered; then determining that the water/dead head condition is not detected, and providing the control signal to continue to allow the pump and motor to run, and repeating step (1) of the method.