The _______ voltage test does not stress the insulation, but will reveal ___________ and contamination in the insulation.

The step voltage test is a method used to assess the condition of insulation without imposing significant stress on it. This type of test involves applying a series of increasing voltages in steps and measuring the insulation's response. It's particularly useful for identifying moisture ingress and contamination within the insulation materials. Moisture and other contaminants can affect the insulation’s effectiveness, leading to reduced performance or potential failure.

The approach focuses on ensuring the safety and longevity of electrical systems by detecting problems early without causing additional damage. The identification of moisture as a significant factor is crucial since it can lead to degradation of insulation and other associated issues, which could compromise the reliability of the substation equipment. Thus, the step voltage test serves as an important diagnostic tool in maintenance protocols.