Analysis of ground leakage issues due to incorrect wiring in low voltage distribution substation area

The low-voltage distribution substation area supplies many users through complex feeders, with leakage faults common in residential and industrial settings, posing serious safety risks. Neutral-to-ground wiring errors causing leakage faults are widespread and challenging to detect due to hidden fault locations and lack of visible insulation breakdown. These issues hinder RCD deployment and are a major cause of electric shocks and fires. This paper reviews the existing three-tier leakage protection and grounding framework, investigates the mechanisms of neutral-ground miswiring, and establishes a residual current model for substations. It also analyzes dangerous voltages in TT and TN-C-S grounding systems from these faults, assessing safety risks for users and proposing targeted countermeasures.