Why are underground secondary faults considered easier to locate?

Underground secondary faults are often considered easier to locate primarily because they are typically shorter in length compared to other types of faults. This reduced distance means that the electrical characteristics of the fault's influence on the system—such as voltage drop, fault currents, or disturbances in the nearby electrical properties—can be identified more easily through various detection methods. Shorter faults can also result in more pronounced changes in system behavior, allowing for quicker pinpointing of the fault area.

Additionally, since underground secondary lines usually have a more contained service area, the testing equipment can more effectively analyze and isolate the location of the fault. Shorter distances mean that the electrical energy can show distinct variations, which can be detected with tools such as fault locators, reducing the time and effort needed for diagnostic work.

In contrast, other factors that might have been suggested, such as greater depths or insulation protection, do not facilitate easier fault location. Greater depth can complicate access and detection, while insulation might not directly correlate with the ability to locate faults. Higher currents can sometimes obscure fault detection because they may create more complexity in the readings.