Product Overview

Transformer bushing is an insulating device that passes through the transformer tank. Its core function is to support and insulate the live conductor passing through the tank, ensuring reliable electrical insulation between the conductor and the tank, as well as between conductors of different phases.

Main Applications

The application scenarios for transformer bushings are closely related to the type of transformer and mainly include:

American-style transformers: Widely use 200A single or double passage bushings that conform to IEEE 386 standards. The double passage bushing is a key component of American-style transformers, converting terminal wiring to ring network wiring and providing an interface for installing lightning arresters.

European-style transformers: Commonly use dry-type bushings.

Wind power transformers: As the core connection device in wind power systems, specially designed dry-type bushings are often used.

Other applications: Also widely used in underground transformers, ring main units, and similar equipment.

Product Features

Transformer bushings mainly come in two types: dry-type and American-style. Their features are compared as follows:

Dry-type bushings (such as those for wind power and European-style transformers)

High safety: No oil, no gas inside, fundamentally avoiding traditional porcelain bushing cracking, oil leakage, or explosion risks.

Excellent performance: Fire and explosion-resistant, pollution-resistant, high mechanical strength, maintenance-free, small size, and lightweight.

Flexible installation: Can be installed horizontally, vertically, or at any angle.

Highly customizable: Flanges and terminals can be specially designed according to user requirements.

American-style bushings (such as 200A single and double passage bushings)

Fully insulated, fully sealed, fully shielded: The design ensures high reliability and a compact structure.

Optimized electric field structure: The inner and outer shields ensure a more uniform electric field distribution.

Safe operation: The uniform outer shield keeps the cable head surface at zero potential to protect people.

Reliable performance: Conductive parts are formed by integrated forging for low contact resistance; unique ratchet structure allows rotational adjustment without affecting performance.

Good waterproof performance: Excellent sealing allows even underwater operation.

Main Technical Parameters (example: American 200A bushing)

Rated voltage: 15kV

Rated current: 200A

Power frequency withstand voltage: 39kV/5min

Lightning impulse voltage: 95kV

Partial discharge: ≤10pC (at 15kV)

Applicable standards: IEEE 386, IEC 60502.4, GB/T 12706.4

Selection and Considerations

Clarify system parameters: Choose the bushing specification according to the transformer's voltage level and rated current.

Confirm interface standards: American-style transformers usually use IEEE 386 compliant interfaces.

Evaluate installation environment: Choose bushings with adequate creepage distance based on environmental pollution level.

Strict installation operation: The installation environment should be dry and clean, with humidity generally below 70%-75%. Lifting and installation should be gentle to avoid collisions.

Ensure reliable sealing: During installation, flange connections must be sealed to prevent moisture and contaminants.

Opt for dry-type products: For high fire safety requirements or harsh environments, dry-type bushings with no oil or gas are recommended.

Application Environment

Transformer bushings are designed to adapt to various complex environments, including:

Normal environment: Widely used in urban distribution networks, industrial parks, commercial centers, and more.

Harsh environment: For high pollution or high humidity areas, select pollution-resistant or fully sealed products.

Special scenarios: New energy projects such as wind and photovoltaic power have higher demands for bushing stability and reliability.