Earth fault or leakage of current is a very common problem in electrical circuits. This leads to unnecessary power loss. The purpose of this project is to develop a system that senses the earth fault in single-phasing system and alerts the user about it. The similar sensing mechanism also can be employed in 3-phase system.   This consists of two electrically isolated current sensors for sensing the amount of current flowing through the circuit. One of the current sensors is connected to phase line of the supply and the other is connected to neutral line. In ideal conditions the amount of current passing through the phase and neutral should be same.  In case of earth fault, the amount of current entering into the circuit will not be equal to the current leaving the circuit. In such situations the microcontroller-based system alerts the user about this in the form of text and audible alerts through buzzer.      

Features:  

1. Instantaneous earth fault identification.
2. Automatic circuit breaker operation.
3. Audio alert through buzzer.
4. Variable trigger point for leakage current.

      The major building blocks of this project are:   

1. Microcontroller
2. Regulated Power Supply
3. Two electrically isolated current sensors.
4. Electromagnetic relay.
5. Buzzer.
6. LED Indicators.

      Software’s used:  

1. PIC-C compiler for Embedded C programming.
2. PIC kit 2 programmer for dumping code into Micro controller.
3.  Express SCH for Circuit design.

      Regulated Power Supply:

               

Block Diagram:            

video: