In a substation, the ground grid covers which area?

The ground grid in a substation is designed to provide a low-resistance path for fault currents and to ensure safety by protecting both personnel and equipment from electrical faults. This grid is essential for grounding, helping to dissipate any fault currents that could arise from equipment malfunction or lightning strikes, thereby preventing hazardous conditions.

The correct answer indicates that the ground grid covers the entire area of the substation, which is important for several reasons. Grounding is not limited to just around individual pieces of equipment, as this could leave unprotected areas where fault currents might travel. By encompassing the entire substation area, the ground grid ensures that all locations within the substation have a foundation for safety by limiting the voltage seen during faults and maintaining the integrity of the electrical system.

This comprehensive coverage helps to prevent step and touch potentials that could harm personnel working in various parts of the substation, thus significantly enhancing safety.

The other choices suggest limitations on the coverage that would be inadequate for effective grounding, potentially leaving gaps where fault currents could cause issues. Therefore, full coverage is crucial for comprehensive safety and operational efficiency in a substation setting.