Abstract: A drain protection device and pump controller for pools, spas, fountains and other fluid containment and circulation systems has a vacuum sensor for sensing a level of vacuum present in the suction conduit leading to the pump(s). The vacuum level is monitored by a computer that controls a vent valve and the pump(s) to reduce the vacuum exerted at a drain. Vacuum criteria may be adjustable and empirically based. Control and monitoring may be verified.

Abstract: A drain protection device and pump controller for pools, spas, fountains and other fluid containment and circulation systems has a vacuum sensor for sensing a level of vacuum present in the suction conduit leading to the pump(s). The vacuum level is monitored by a computer that controls a vent valve that can vent to atmosphere to reduce the vacuum exerted at a drain. In applications with a flooded pump, e.g., above-ground pools, the vent valve may control the discharge of an accumulator that injects fluid pressurized by the return line into the suction conduit to reduce the vacuum therein. The computer also controls the pump(s) present in the circulation system, viz., turns them off to relieve vacuum when a drain is occluded and also runs them at the selected speed based upon a schedule. The vacuum criteria for vacuum reduction may include progressively sensitive values, some of which may be empirically based. Vacuum criteria may be maintained based upon the operational state of the circulation system, e.g.