DIY TROUBLESHOOTER

Earthing

           The earth is made up of materials that is electrically conductive. A fault current will flow to 'earth' through the live conductor, provided it is earthed .  This is to prevent a potentially live conductor from rising above the safe level .  All exposed metal parts of an electrical installation or electrical appliance must be earthed .

            The main objectives of the earthing are to :

   1) Provide an alternative path for the fault current to flow so that it will not endanger the user

   2) Ensure that all exposed conductive parts do not reach a dangerous potential

   3) Maintain the voltage at any part of an electrical system at a known value so as to prevent over current or excessive voltage on the

appliances or equipment . 

            The qualities of a good earthing system are :

   1) Must be of low electrical resistance

   2) Must be of  good corrosion resistance

   3) Must be able to dissipate high fault current repeatedly