A New Summary on the IEC Protection Against Electric Shock

The International Electrotechnical Commission (IEC) publication 60364-4-41 “Electrical installations of buildings” fifth edition offers a layout rationalized of complete protective measures against electric shock. To provide an overall analysis of the protection by automatic disconnection of supply, the author suggests a unified model for all grounding systems (TN, TT, and IT systems), including common and global grounding systems that assist in giving an explanation to the IEC approach. For electrical risk assessment, this paper proposes the analysis of risk exposure in analogy with dynamical collision problems.