What is Earth Pit?
In EB system an earth pit refers to a pit dug in the earth with sand, glay and salt mixing. It is used to safety towards from short circuit current.
This type of safety work prevent from current flows from high voltage to low voltage. When ever we open the refrigerator in rainy season, if any short circuit inside of the refrigerator, we have not aware that time a live wire line voltage is available. It is very dangerous to human health.
We know that current choose the lowest resistance path.A resistance of the human body is about 300 ohms and the earth is very low (in our project maintenance the earth resistance 2 to 6 ohms) so that leakage current will go into the earth pit and ground wire. CIRCUIT DIAGRAM: PIPE EARTHING:
Pipe earthing is the best form of earthing and it cheap also in the type of earthing a GI pipe of 38 mm dia and 2 meters length was normally in vertically in ground to as earth electrod but depth upon the soil condition, there no hard and fast rule for this.
Here my project is designed to maintain its resistance with ground level water moisture. If water moisture goes wet level and the earth pit resistance also increase vice versa.
My project and associated adc act as resistance measurement. A set value of the resistance is 3 ohms and it is pre-settable type.
The current resistance measurement set up from the under soil moisture water level goes low. This setup act as high resistance, this resistance level message SMS was sent to electrician. From this reference out MCU sends a command to solenoid valve. This solenoid valve is attached to out water pipe, when it is opened water goes to earth pit to ground level. At his action its resistance goes low from out set value.