What should a substation grounding system ensure to prevent exposure during a ground fault?

The objective of a substation grounding system is to ensure safety and prevent potential harm during a ground fault. The correct answer highlights that the grounding system must be designed and implemented in a way that avoids fatal electrical shock, which is the most serious outcome of electrical exposure.

Grounding systems serve to provide a low-resistance path for fault currents, safely directing them to the ground, which minimizes the risk of electrical shock to personnel and protects equipment from damage. If the grounding system is effective, it significantly reduces the potential for dangerous scenarios, including those that could lead to fatal outcomes.

In this context, while minor shocks, burns, or loss of consciousness could occur under improper conditions or with inadequate protection, the primary goal of the grounding system is to prevent the most severe consequences—namely, fatal electrical shocks. Therefore, this is the pivotal aspect emphasized in grounding system design within substations.