Analysis of Ground Fault Protection in Low Voltage Distribution TN-S System

In this study, typical cases are combined to analyze the technical requirements for the TN-S system to prioritize the use of short-circuit overcurrent protection over ground fault protection. The necessity of adopting residual current action protection as ground fault protection is elucidated, as well as the importance of auxiliary equipotential bonding in reducing contact voltage. Various protective measures are proposed along with their respective roles and applicable conditions. The analytical process and resulting conclusions hold significant importance for grounding fault protection in engineering design and application.