Booster pump flow controller (water presence)

It is used to protect the booster pump array from lack of water. It is connected with a 1/4″ spark plug electrode and directly drives a motor up to 2HP. It is installed directly in a socket outlet. Its operation is based on measuring the change in resistance between the electrode and the ground. As soon as it is supplied with mains voltage and after a preset delay of 30 seconds it detects the presence of water. If there is water, the power relay is activated and directly drives the motor of the booster pump, if not then the relay remains deactivated until water appears. The use of safe low AC voltage between electrode and ground prevents electrolysis. The water impedance should be less than 20 kΩ.