Earthing equipment, In electrical engineering the earth or ground might be the reference point in an electrical circuit by which voltages are measured, or a return path for electric current or a direct connection to Earth. Earthing equipment utilizes electrical circuits which can be connected to the ground/earth for varying reasons. Exposed metal parts are connected to the ground when using mains powered equipment in order to prevent any contact that may occur with a dangerous voltage should the electrical insulation fail. The term Earth or ground are extremely common in electronics or electrical applications. In the USA the words or terms ground and grounding are used to signify that electrical equipment has been securely bonded to the ground. In the UK we use the terms earth or earthing.