It is the Facet Of Extreme Busbar Machine Rarely Seen, However That's Why Is required
An earthing system (UK and IEC) or grounding system (US) connects specific parts of an electric power system with the ground, typically the Earth's conductive surface, for safety and functional purposes. Normal imbalances in the circuit would create small equipment to ground voltages, a failure of the neutral conductor or connections would allow the equipment to go to full 120 volts to ground, an easily lethal situation. The PEN must be suitably reinforced against failure, as an open circuit PEN can impress full phase voltage on any exposed metal connected to the system earth downstream of the break. The alternative is to provide a local earth and convert to TT. In a TT (Latin: terra-terra) earthing system, the protective earth connection for the consumer is provided by a local earth electrode, (sometimes referred to as the Terra-Firma connection) and there is another independently installed at the generator. The main attraction of a TN network is the low impedance earth path allo...