Dissipation/Power Factor Measurement (Tan Delta)

The condition of the insulation is essential for secure and reliable operation of your transformer. Measuring capacitance and dissipation/power factor helps you to determine insulation condition in bushings or between windings.

Changes in capacitance can, for example, indicate mechanical displacements of windings or partial breakdown in bushings. Aging and degradation of the insulation, coupled with the ingress of water, increase the amount of energy that is converted to heat in the insulation. The rate of these losses is measured as dissipation factor.

With our testing systems, you can even determine the capacitance and dissipation/power factor at variable frequency. Therefore, aging phenomena can then be detected earlier, and corresponding action such as repair, oil treatment or drying can be initiated.

Recommended solutions for dissipation/power factor measurements on power transformers


Three-phase power transformer test system

CPC 100 + CP TD1

Multi-functional test system for various high-voltage assets

CPC 80 + CP TD1

Dedicated power/dissipation factor test system




High-precision measuring system without source and reference capacitor