The system consists of two parts, a point capacitance level probe which is located in the priming tank and a dedicated electronic controller mounted external to the tank. The APP system provides a fully automatic smart pump priming system. Solid state outputs can be used to directly drive a solenoid and clutch, or used as digital inputs for other control and monitoring equipment. The controller features solenoid anti-splash and sensitivity controls, and the clutch has an automatic resetting 90s timer. The probe operates on a capacitance detection system so works in dirty water as well as contaminated oily liquids. Designed to operate with a +12VDC negative earth system.