ABSTRACT
Grounding practices for low-voltage systems (i.e., voltage-to-neutral not exceeding 1 kV) and safety requirements adopted around the world do differ. The specific role of system grounding (i.e., TT, TN, IT) to limit the risk of electric shock is herein analyzed, and important definitions provided by the International Electrotechnical Committee (IEC) are provided. The protective measure “automatic disconnection of supply” requires the partnership between protective devices, which promptly disconnect the circuit in the event of a ground-fault, protective conductors (PEs), which facilitate such disconnection, and protective equipotential bonding (i.e., main and supplementary), which reduce touch voltages, regardless of the type of system ground.
