EN Bushing
Complete Industry Guide for EN Standard Transformer Porcelain Bushing
Complete Industry Guide for EN Standard Transformer Porcelain Bushing
1. Basic Definition and Core Introduction of EN Bushing
EN standard transformer bushing is the essential insulating fitting designed according to EN‑50180 and EN‑50243 industrial specifications, widely used for oil‑immersed single‑phase and three‑phase power transformers in European‑standard power‑distribution networks. The EN porcelain bushing creates safe conductive channels for internal transformer conductors to pass through the grounded metal oil tank, separating live copper terminals from the earthed transformer shell with high‑strength ceramic insulation layers.
Low‑voltage EN bushings normally cover rated voltage grades from 1.2kV up to 36kV, with adjustable rated‑current specifications from 55A to 1200A. As a core power‑transmission insulator component, every qualified EN bushing completes strict factory dielectric‑withstand testing, partial‑discharge inspection and creepage‑distance calibration before shipment. Many power‑grid contractors, transformer manufacturers and electrical‑engineering buyers search for high‑performance EN bushing, EN standard porcelain insulator, LV transformer bushing and oil‑immersed transformer accessories during equipment procurement. Proper‑selected EN‑compliant bushings cut down transformer short‑circuit risk, stop electric‑leakage accidents and extend the whole service cycle of distribution‑transformer hardware.
2. Main Features, Core Advantages and Common Application Scenarios for EN Standard Bushing
Multiple outstanding structural and material features make porcelain‑type EN bushing the mainstream insulator choice for global power‑distribution equipment. First, its high‑density glazed‑porcelain outer shell delivers powerful anti‑corrosion, ultraviolet‑resistance and dust‑proof performance. The smooth glazed surface slows down pollutant accumulation in heavily‑polluted industrial zones, coastal humid districts and outdoor substation environments. Second, the built‑in copper conductive rod offers stable large‑current transmission capacity without serious over‑heating under long‑time full‑load working conditions.
The complete set of mounting terminals contains single‑hole, double‑hole and four‑hole flange‑type connectors to fit different transformer‑tank opening sizes. The standardized thread size follows unified EN industrial thread parameters, supporting fast installation, quick disassembly and convenient spare‑part replacement.Key competitive advantages of EN porcelain transformer bushing are listed below
- Outstanding dielectric strength that blocks high‑voltage breakdown and surface flash‑over accidents
- Strong mechanical shock resistance against vibration generated by transformer operation and nearby construction
- Stable insulating property under extreme‑temperature shifts from minus 40℃ to plus 40℃
- Low power consumption and tiny partial‑discharge value during daily power transmission
- Affordable factory‑direct cost and customizable dimension parameters for special‑model transformers
- Long‑term anti‑aging porcelain material for 20‑30 years of normal service life
EN‑standard bushings serve multiple electrical‑industry scenarios. They are widely fitted on oil‑immersed distribution transformers for residential power grids, industrial factory power supply stations, outdoor overhead‑line transformer cabinets, mining‑site power‑transfer devices and commercial‑area power‑distribution equipment. Both low‑voltage 1.2kV‑grade EN bushings and medium‑voltage 15kV‑34kV high‑voltage EN insulators can match single‑phase and three‑phase transformer equipment for civilian and industrial power projects.
3. Complete Technical Dimension Parameter Table for 1.2kV EN‑Standard Porcelain Transformer Bushing (125A‑250A)
This mainstream low‑voltage EN bushing series includes eight common installation types covering single‑bolt, single‑hole, double‑hole and four‑hole flange terminals, and all dimension data adopts millimeter as the measuring‑unit.
表格
| Serial Number | Complete Model | Overall Height H | Insulator Height h1 | Thread Section Height h2 | Mounting Thread Md | Terminal Rod Diameter Φd | Flange Width B | Mounting Hole n*Φd1 | Flange Plate Thickness t | Rated Creepage Distance | Component Code |
|---|---|---|---|---|---|---|---|---|---|---|---|
| 1 | EN‑1.2KV‑125A‑single bolt | 150 | 81 | 29 | 3/8‑16UNC | 16 | 29 | 1*14 | 6.35 | 25 | 12XD.401.001 |
| 2 | EN‑1.2KV‑125A‑single hole | 165 | 81 | 29 | 3/8‑16UNC | 16 | 29 | 1*14 | 6.35 | 25 | 12XD.401.001 |
| 3 | EN‑1.2KV‑125A‑double hole | 181 | 81 | 29 | 3/8‑16UNC | 16 | 76.2 | 2*14 | 6.35 | 25 | 12XD.MBTG.055 |
| 4 | EN‑1.2KV‑125A‑four holes | 218 | 81 | 29 | 3/8‑16UNC | 16 | 88.9 | 4*14 | 6.35 | 25 | 12XD.MBTG.090 |
| 5 | EN‑1.2KV‑250A‑single bolt | 165 | 81 | 39 | 1/2‑13UNC | 21 | 29 | 1*14 | 6.35 | 25 | 12XD.401.003 |
| 6 | EN‑1.2KV‑250A‑single hole | 175 | 81 | 39 | 1/2‑13UNC | 21 | 29 | 1*14 | 6.35 | 25 | 12XD.401.002‑2 |
| 7 | EN‑1.2KV‑250A‑double hole | 191 | 81 | 39 | 1/2‑13UNC | 21 | 76.2 | 2*14 | 6.35 | 25 | 12XD.401.002 |
| 8 | EN‑1.2KV‑250A‑four holes | 228 | 81 | 39 | 1/2‑13UNC | 21 | 88.9 | 4*14 | 6.35 | 25 | 12XD.401.003‑1 |
All models share the standard tank‑opening dimension of Φ48mm for transformer‑shell installation, and the outer‑side porcelain‑glaze diameter keeps 35mm for the main insulating body. Buyers can select proper flange‑hole layouts according to their transformer‑tank reserved mounting holes.
4. Frequently Asked Questions for EN‑Standard Transformer Bushing
Q1
Is the EN porcelain transformer bushing durable for long‑time outdoor operation
High‑grade electrical porcelain raw‑material brings outstanding anti‑aging performance. Under regular inspection and normal‑pollution working environments, qualified EN bushing keeps stable insulating performance for 20‑30 service years. Its glazed outer surface resists sunlight ultraviolet damage, rain‑water corrosion and industrial grime erosion. Service life will shorten only when the porcelain shell suffers cracks, heavy‑duty chemical pollution or frequent lightning‑surge impact.
Q2
What are the daily maintenance steps for EN‑type porcelain bushing
Carry out visual inspection every six months to check porcelain bodies for cracks, chips, scratches and thick dust deposits. Clean the glazed surface with dry soft cloth or neutral detergent to remove accumulated industrial dirt. Run insulation‑resistance testing and partial‑discharge detection every three to five operation years. Check the tightness of flange mounting nuts and threaded connecting terminals, and replace ageing rubber sealing gaskets regularly to stop transformer‑oil leakage. Never use sharp hard objects to scrape the porcelain glaze layer.
Q3
Can I customize voltage, current and mounting‑hole specifications of EN bushings
Yes. Most manufacturers support customized production for rated‑voltage grades, rated‑current parameters, overall height, flange‑hole quantity and thread specifications. Custom‑made EN bushings fit special‑size oil‑immersed transformers, mining‑transformer equipment and high‑altitude power‑distribution devices.
Q4
What common faults will happen on the EN porcelain bushing
The typical‑seen failures contain porcelain‑shell crack, sealing‑ring oil leakage, surface flash‑over caused by heavy dirt, loose connecting‑terminal heating and internal insulation ageing. Once obvious porcelain cracks appear, replace the whole bushing right away, because cracks allow moisture to enter the insulating core and trigger transformer short‑circuit breakdown.
Q5
What industrial standards must qualified EN bushings comply with
Qualified products need to pass EN‑50180, EN‑50243 and IEC‑60137 international transformer‑bushing standards. Every finished unit must finish power‑frequency withstand‑voltage testing, creepage‑distance inspection, mechanical‑strength impact test and partial‑discharge screening before factory delivery.
5. Industry‑Wide Qualification and Certification Information for EN Transformer Bushing
Categories
Contact Us
Contact: Tianjin Delda Trading Co., Ltd
WhatsApp: +86 13662056855
Tel:
E-mail: solomon20210701@tjxddq.com
Add: Unit‑101, Workshop 3, Bozhong Automobile Industrial Park, No.5 Xianghui Road, Intersection of Xianghui Road and Gaoying Road, Beizhakou Town, Jinnan District, Tianjin, China