What should a power system ground wire be heavy enough to carry?

The correct response is focused on the need for a power system ground wire to have sufficient capacity to carry the current for which the circuit is fused. This is essential for ensuring that the ground wire can safely redirect any potential fault current without overheating or failing. Proper grounding protects both equipment and personnel by directing excess electrical current safely to the ground, minimizing the risk of electric shock or fire hazards.

Fusing is designed to protect the circuit from excess current, and the ground wire must be capable of managing up to that same level of current to function effectively. This alignment ensures that, in the event of a fault, the circuit can activate the fuse to interrupt the fault condition without risking damage to the grounding system or equipment.

While other options suggest important functions of grounding, such as addressing static charge or potential fault currents, they do not precisely align with the requirement for the ground wire's capacity relative to the circuit’s protection, which is crucial for overall system safety and reliability.