Single-control UP pool (water storage) :A(red)-Upper water level control point. When water level gets to A point,the probe Contact water and controller can stop the pump by auto.B(blue)-Lower water level control point. When water level gets off B point,the probe out of reach water and controller can start the pump by auto.C(black)-Should be placed in bottom of pool as the common line.D(green) and E(yellow)are connected with C (black). Single-control DOWN pool(drain water):E-Upper water level control point. When water level gets to E point,the probe Contact water and controller can start the pump by auto.D-Lower water level control point. As liquid level gets off D point,the probe out of reach water and controller can stop the pump by auto.C-Should be placed in bottom of pool as the common line.A and B-disconnected Lack of water protection:C and D-Lower water level control points. When water level gets off this point,C or D probe out of reach water and controller can stop the pump by