What is Earthing?
The term ‘earthing’ means the electrical connection of the non-current carrying metallic parts of the machines and electrical appliances and the neutral wire of the supply systems to the general mass of the earth by a low resistance lead wire which gives at all times the swift discharge of current without causing any danger.
The main function of the earthing is to save the man from getting an electrical shock in case of flow of leakage current to earth due to insulation failure. if an electrical installation is connected to the earth it will ensure no conductor will attain dangerously high voltage in this installation.
If the frame or body of the motor is connected to the earth then the operator of the motor will not get any electric shock, even the insulation of the motor winding is broken thus flowing leakage current and making the metal body of the motor is charged condition.
Types of Earthing:
There are four types of earthing are generally used:
i. Plate Earthing: It is used in domestic electrical installation.
ii. Pipe Earthing: It is used in motor installation and sub-station earthing.
iii. Rod or Spike Earthing: It is used in transmission and distribution supply lines.
iv. Wire or Strip Earthing: It is used in hilly areas.