During testing, which of the following could indicate a failure in equipment insulation?

Low insulation resistance is a critical indicator of potential failure in equipment insulation. Insulation resistance testing is essential for assessing the integrity of electrical insulation in various components, such as cables and transformers. A low reading can suggest that there is a breakdown in the insulation material, which can lead to unintended current paths, increased risk of short circuits, or other electrical failures.

In practical terms, equipment with low insulation resistance may be susceptible to moisture ingress, contamination, physical damage, or aging—all factors that can compromise insulation integrity. Therefore, monitoring insulation resistance helps in maintaining equipment safety and functionality.

In contrast, high insulation resistance indicates good insulation quality, while stable temperature readings and consistent voltage levels do not directly convey information about insulation condition. These parameters focus on thermal stability and voltage behavior rather than the effectiveness of insulation.