How to Select Potting Compounds for Three-Phase Copper Busbars?Comparison Between High-Tg Low-CTE and Flexible Epoxy Grades

Key performance indicators for three-phase copper busbar potting compounds include insulation, oil resistance, thermal cycling resistance, CTE and crack resistance. Elaplus offers three material solutions for three-phase copper busbars: EP 1716, EP 1721-1 and SIPA 3005. EP 1716 features high Tg and low CTE; EP 1721-1 adopts a flexible epoxy system; SIPA 3005 is a one-component heat-curable self-leveling silicone. Why Do Three-Phase Copper Busbars Require Potting? Three-phase copper busbars are widely applied in: They are responsible for high-current transmission and electrical connections. Adhesives used here mainly serve insulation protection, thermal management, shock-resistant fixing and anti-corrosion. High-Tg & Low-CTE Option: EP 1716 EP 1716 Two-Component Epoxy Potting Compound EP 1716 is a 100:5 epoxy potting compound with high Tg and low CTE. Recommended applications: Copper and resin feature different coefficients of thermal expansion. Reducing CTE helps minimize interfacial stress generated during temperature cycling. Need Flexible & Crack-Resistant Material? EP 1721-1 Two-Component Flexible Potting Compound EP 1721-1 is a 3:1 flexible epoxy potting compound with low stress, excellent crack resistance and thermal stability. Suitable for structures demanding strong buffering against thermal displacement and mechanical stress. One-Component Self-Leveling Solution SIPA 3005 One-Component Addition-Cure Sealant SIPA 3005 is a one-component heat-curable, self-leveling silicone. Designed for specific copper busbar sealing and insulation scenarios requiring one-component processing and self-leveling technology. Three-Phase Copper Busbar Material Selection Comparison Grade Material Type Core Advantages EP 1716 Epoxy High Tg, Low CTE EP 1721-1 Flexible Epoxy Low stress, Crack resistance SIPA 3005 Silicone One-component, Heat-curable, Self-leveling FAQ – Common Questions on Busbar Potting Why is CTE particularly critical for busbar potting? Copper busbars and resins expand to different extents under temperature variation. Improper CTE matching may lead to interfacial stress and cracking. Does flexible epoxy have lower strength? Reliability cannot be judged merely by the term “flexible”. Validation should be…