Earthing and Bonding - What does it do?

This paper is based one presented at the IEE BETNET conference in Hong Kong in October 2005, which itself was based on a paper given to an ERA Technology Conference in June 1997. The principles, if not the practice, involved in earthing an electrical system are the same regardless of the potential at which it operates. Earthing introduces hazards but allows fault currents to flow, which can be used to operate protective devices. These can protect against shock, fire and burn by disconnecting the supply to the fault. Bonding reduces the potential between simultaneously accessible parts, usually without reducing the potential to true earth