high‑voltage epoxy resin transformer bushing with solid copper conductive rod
Introduction
Power‑system engineers frequently compare resin bushing and traditional porcelain bushing while choosing transformer penetrating insulating accessories. Both two kinds of high‑voltage bushing complete the task of conductor exporting and electrical isolation. Nevertheless, differences in raw‑material property, manufacturing craft, environmental adaptability and maintenance cost decide their applicable working‑condition boundaries. This passage carries out all‑round comparison between resin bushing and porcelain bushing and delivers practical selection suggestions for power‑equipment purchasers and electrical designers.
Core Performance Comparison Table
| Comparison Dimension | Epoxy Resin Bushing | Traditional Porcelain Bushing |
|---|
| Overall Weight | Light, 30%‑40% lighter | Heavy, big load for transformer mounting flange |
| Impact‑Resistance Capacity | Excellent, not easy to crack under collision | Fragile, high breakage risk during transit and installation |
| Partial‑Discharge Level | Stable below 5pC | 10‑30pC for common‑grade products |
| Pollution‑Resistant Capacity | Strong, smooth resin outer shell resists dust adhesion | Glaze surface easily accumulates fouling, regular cleaning required |
| Waterproof and Sealing Property | Integrated casting, zero gap between shell and copper core | Multi‑part assembly, potential leakage risk on splicing seams |
| Installation Angle | Support vertical and 30‑degree inclined mounting | Most models only adapt to vertical installation |
| Customization Flexibility | Flexible on current specification, flange size and creepage distance | Limited fixed mould size, high cost for personalized modification |
| Service‑Life Maintenance | Low‑maintenance, anti‑aging epoxy material | Prone to glaze ageing, crack and salt‑fog erosion outdoors |
Deep‑Dive Analysis on Resin‑Bushing Strengths
One‑piece cast molding is the biggest competitive advantage for resin bushing. Without assembled stitching gaps, the whole insulating body avoids hidden dangers such as air‑cavity breakdown and oil seepage. For outdoor substations, coastal salt‑fog districts and industrial heavily‑polluted zones, anti‑pollution resin bushing greatly lowers routine maintenance frequency. The lightweight feature simplifies on‑site installation work and reduces long‑term mechanical fatigue damage to transformer tank metal structures.
Resin bushing also performs well in high‑altitude regions over 1000 meters. Manufacturers raise outer‑surface creepage distance of epoxy shell to adapt thin‑air insulation‑attenuation environment. Multiple‑current‑grade options including 55A, 315A, 630A meet low‑current instrument transformers and heavy‑current main power transformers separately.
Suitable Working‑Condition for Porcelain Bushing and Resin Bushing
Choose standard resin bushing for oil‑immersed distribution transformers, outdoor power‑grid equipment, mobile electrical devices and projects with strict anti‑vibration requirements. Reinforced anti‑pollution resin bushing is the first pick for chemical plants, coastal power stations and mining industrial zones. Porcelain bushing can be adopted for indoor fixed‑type transformers with clean environment and sufficient installation bearing capacity.
Common‑seen Selection Mistakes for Resin Bushing
Lots of buyers only focus on rated voltage and ignore rated‑current parameter. The copper‑rod cross‑section of resin bushing matches working current. Small‑current 55A resin bushing cannot undertake heavy‑current load above 300A. Besides, purchasers need to confirm installation angle, altitude limit and local pollution level before confirming bushing specifications.
