Which condition must be met for grounding in high voltage systems?

In high voltage systems, ensuring safety and reliability is paramount, and one critical aspect of this is the grounding system. The requirement for the ground wire to be larger than the phase conductors stems from the need to handle fault currents without experiencing excessive heating or resistance. A larger ground wire provides a lower impedance path for fault currents, allowing them to safely dissipate to the earth rather than through other components of the electrical system.

This design consideration is rooted in the prevention of electrical hazards, as an inadequate ground size may not effectively carry the fault current in the event of a short circuit or equipment failure, which could lead to catastrophic failures or pose safety risks to personnel. Therefore, using a ground wire that is suitably sized compared to the phase conductors is essential for maintaining system integrity and safety.

The other choices fail to provide the necessary standards for grounding in high voltage systems. While any gauge, smaller wires, or those rated for low voltage do not meet the rigorous requirements needed for high voltage systems. Proper grounding is a critical component of high voltage installations to ensure operational safety and compliance with electrical codes.