What happens to the current flow when there is a fault in the power system during a ground resistance test?

In a ground resistance test, the primary focus is to measure how effectively the grounding system conducts current to the earth, particularly during fault conditions. When a fault occurs in the power system, such as a short circuit, it creates a significant difference in electrical potential, resulting in an increased fault current. The current flow increases significantly in response to the fault due to its low impedance path through the grounding system to the ground.

This surge in current is critical for protective devices to detect and isolate the fault quickly. A properly functioning grounding system should allow this increased current to dissipate into the earth to minimize the risk of equipment damage and ensure safety. Therefore, the rise in current flow when a fault occurs is a key aspect tested during ground resistance tests, highlighting the importance of effective grounding in punctuating system reliability and safety.