One of the reasons for installing protective grounds is to prove what?

Installing protective grounds is essential for ensuring electrical isolation during maintenance or repair work. This isolation is crucial because it protects workers from potential electrical hazards, such as fault currents or accidental re-energization of electric lines. When protective grounds are installed on a system, it effectively creates a safe path for any fault current to flow to the ground, minimizing the risk of shock or electrocution for the linemen working on or near energized equipment.

This practice not only enhances safety but also provides a verification system for workers to confirm that the line is de-energized and that it is safe to perform their tasks. By establishing this level of safety through electrical isolation, linemen can confidently conduct their work without the constant fear of electric shock from residual energy in equipment.

The other options, while related to electrical systems management, do not correctly align with the primary purpose of installing protective grounds. Ground effectiveness pertains to the ability of the grounding system to dissipate fault currents, while voltage reliability and line efficiency address performance and operational aspects rather than immediate safety concerns.