To ensure proper ground resistance levels, what should the average resistance ideally be for a 3-point fall-of-potential earth resistance test?

The average resistance level that is typically aimed for in a 3-point fall-of-potential earth resistance test is below 25 ohms. This standard is established to ensure that the grounding system is effective in providing a safe path for fault currents, reducing the risk of electrical shock, and minimizing equipment damage during fault conditions.

Maintaining a ground resistance value of 25 ohms or lower is crucial because it signifies that the grounding system is capable of quickly dissipating electrical surges. If the grounding resistance were to be higher, it could result in inadequate dissipation of electrical energy, which raises the risk of hazards associated with electrical faults, such as equipment failure or ignition of flammable materials.

This threshold aligns with safety standards and practices, ensuring that all electrical systems are properly safeguarded against potential electrical hazards. Proper grounding is a critical element in electrical safety, especially in environments where explosive materials may be present, as in military applications.

Thus, aiming for a resistance level below 25 ohms during testing is a best practice to ensure safety and compliance with electrical explosive safety protocols.