Porcelain Transformer Bushings for 11kV–245kV Transformers

Porcelain transformer bushings provide the insulated electrical connection between transformer windings and external power systems. ASIAPOWER manufactures DIN, ANSI, BS and AS standard porcelain transformer bushings for distribution transformers, power transformers and substation equipment from 11kV to 245kV. All bushings are engineered for high dielectric strength, low partial discharge levels and long-term outdoor operation.

• 11kV–36kV Distribution Transformer Bushings
• 72.5kV–145kV Power Transformer Bushings
• 245kV Substation Transformer Bushings
• DIN Standard (EN 50180 / 50181)
• BS Standard (BS EN 60137)
• ANSI Standard (IEEE C57.19.01 / C76.1)
• AS Standard (AS 60137 – Australia / New Zealand)

Applications of Transformer Bushings

• Distribution Transformers (11kV–36kV)

• Power Transformers (72.5kV–145kV)

• Substation Transformers

• Renewable Energy Substations

• Industrial Power Distribution Systems

• Utility Transmission Networks

• Oil Immersed Transformers

• Outdoor Transformer Installations

FAQ

Q：What is a transformer bushing?

A transformer bushing is an insulated electrical device that allows a live conductor to pass safely through the grounded tank of a transformer. It provides both electrical insulation and mechanical support, preventing current leakage and flashover between the high-voltage conductor and the transformer housing.

Q：What is the difference between porcelain and composite bushings?

Porcelain bushings are made from high-grade ceramic material offering excellent dielectric strength, UV resistance, and long-term stability, but they are heavier and more prone to breakage from impact. Composite bushings use a fiberglass reinforced epoxy tube with silicone rubber sheds. They are lighter, offer superior hydrophobic properties (water beading), better pollution performance, and higher mechanical flexibility, making them ideal for contaminated environments and seismic zones.

Q：How do I select a transformer bushing?

Select based on: rated voltage (e.g. 11kV, 24kV, 33kV, 36kV); rated current (typically 200A to 2500A); insulation type (porcelain or composite); creepage distance (for pollution class: light, medium, heavy); mounting flange standard (IEC or ANSI); ambient and oil temperature ranges; and short-circuit current withstand capability.

Q：What standards apply to transformer bushings?

AsiaPower bushings comply with IEC 60137 (most common international standard), ANSI/IEEE C57.19.01 and C57.19.100 (North American standard), and CSA (Canadian standard upon request). Factory routine tests and type tests are available per customer requirements.

Q：What voltage ratings are available?

We manufacture transformer bushings for medium voltage applications from 3.6kV up to 36kV, including 11kV bushings, 24kV bushings, 33kV bushings, and 36kV bushings. Custom voltage ratings are available for OEM projects.

Q：Can transformer bushings be customized?

Yes. AsiaPower offers full OEM customization including customer brand and logo on nameplate; special flange dimensions and mounting hole patterns; extended creepage distance for high pollution areas; custom conductor material (copper, brass, aluminum); specific terminal types (stud, flat pad, cable lug); and packaging with customer labels.

Q：What tests are performed?

Each transformer bushing undergoes routine tests: dielectric withstand (power frequency and impulse), partial discharge measurement, leakage current test, oil leakage test, and dimensions verification. Type tests including thermal cycling, bending moment, salt fog pollution test, rain test, and radio interference voltage (RIV) are available upon request.

Q：Do you provide OEM manufacturing?

Yes. AsiaPower is a technical OEM supplier. We manufacture transformer bushings under your brand name, provide technical drawings for approval, supply factory test reports, and support EPC contractors, transformer manufacturers, and utility projects worldwide with full traceability and engineering documentation.