What is the purpose of outside grounds used with an equipotential ground?

The purpose of outside grounds used with an equipotential ground is primarily aimed at enhancing safety measures in electrical systems. Equipotential grounding is crucial for ensuring that all conducting surfaces are at the same electrical potential, which helps to prevent dangerous voltage differences that could lead to electric shock. When outside grounds are used in conjunction with equipotential grounding, they serve to provide a pathway for fault currents, which can help direct potentially hazardous electrical energy away from individuals and equipment.

This effectively enhances the overall safety of the electrical system by reducing the risk of electric shock and electrical fires, thereby ensuring a safer working environment. The outside grounds play a critical role in system stability and safety, by improving the performance of overcurrent protection devices that are designed to detect faults. While other choices mentioned may seem relevant in different contexts, the salient role of outside grounds is rooted in their contribution to safety and fault management within electrical systems.