A hole needs to be digged at the lowest place in the celler that have water incomming problems. The hole is about 0.5 x 0.5 x 0.5 meter, at the bottom a large water pump is mounted. Then the different water levels was measured, so we know how to make the sensors
We just took some old thick flamingo plate, and fastened 4 thick wires. The longest is the ground connection, this one is always covered by water. Sensor 1 (STOP) is placed just over the top of the pump, so the pump is always covered by water. Sensor 2 (START) is placed 5-7 cm over the pump Sensor 3 (ALARM) is places 5-7 cm under the top edge of the hole. All electronics was mounted inside this nice plastic case, so it looks really prof. The 10 pump count LEDs is to show if the pump has been active since last time we was in the cellar. this tells if water is comming into the hole or not. The 10 counting LEDs uses a common resistor to ground. The complete box with electronics before it was all glued into the case with hot melt glue. First we used a mecanical relay, to test with. Later it was replaced with a solid state relay, with no moving parts, this gives a much longer life time. Closeup of electronics, just made on a prototype vero board. Inside the complete box, ready for testing. The plug for the sensors is a XLR type. The waterpump powercoard is a waterproff type. The 12V is unregulated, just use a small 9V AC transformator and a bridge and a 2200uF cap
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