Unlocked by Ergon: Insulating liquids test – lesson #8: Electrical measurements for insulating oils

To understand dissipation factor measurements and their importance in assessing insulating liquid condition.

Lesson description

This lesson explains the principles of dissipation factor (tan delta / power factor) measurements and their relationship to dielectric losses in insulating liquids. It clarifies how polar contaminants, oxidation products, water, and conducting impurities increase dielectric losses and affect measurement results.

The lesson also explains the relationship between tan delta, resistivity, and permittivity and highlights why measurement conditions such as temperature and frequency must be carefully controlled. Practical interpretation is linked to ageing, contamination, and treatment decisions.

Learning outcomes

· Explain the meaning of dissipation factor and its role in evaluating dielectric losses.

· Understand the relationship between tan delta, resistivity, and permittivity.

· Identify the main contaminants and ageing products that affect electrical measurements.

· Recognise the importance of temperature control and standardised methods.

·  Use DDF results as part of overall oil condition assessment.

Content of this lesson is fully vendor agnostic but it is sponsored by Ergon!