Useful Technique for Analysis of Fluid-Filled Capacitors

Fluid-filled metallized-polymer-film capacitors have unique failure mechanisms, many of which are related to insufficient fluid level, improper installation geometry, or both. Although such failures can be analyzed using X-ray testing equipment, it is often impractical or cost-prohibitive. This article describes some of the failure modes observed in fluid-filled capacitors and explains how to analyze them easily and inexpensively.