I am making a automatic water level controller for my home,I am new to Electrical Engineering and learning things. I am using a MCU to turn ON/OFF submersible water pumps using some float switch to detect water level in overhead tank. This pump has Start Switch(Normally Open), and stop switch(Normally Closed), connected with some contactor. For my project I want to replace these mechanical switches with Relay(Electromechanical Relay)- 5V 10A, which is controlled using MCU. But I am stuck with how to interface contactor (ON/OFF) mechanism with Relay (NO and NC) contacts. I am planning to use general purpose relay, something like this but of 10A capacity: General purpose capacitor. Here is an block diagram for it. .Submersible pump here is of 2HP, 230V,Single phase. Can anyone suggest me how to do it or direct me read any such article that helps? Thanks in Advance!
If you want to keep the existing manual Start/Stop buttons (highly recommended!), you will need your MCU to control two relays. The Start relay Normally Open contacts should be wired in parallel with the existing Start button, and the Stop relay Normally Closed contact wired in series with the existing Stop button. The MCU should pulse either relay for 100 mS or so (whatever time is required for reliable operation...)