2500kVA 35kV Oil-Immersed Distribution Transformer

The 2500kVA 35kV Oil-Immersed Distribution Transformer is an oil-immersed distribution transformer with a rated capacity of 2500kVA and a high-voltage side rating of 35kV.

Utilizing insulating oil to simultaneously provide both electrical insulation and heat dissipation, it reliably converts high-voltage electrical energy into medium-to-low voltage energy, and is widely employed within the distribution segments of power systems.

Key Features:

Type: Oil-Immersed Distribution Transformer

Capacity: 2500kVA (Medium-to-large distribution capacity)

Voltage Rating: 35kV High-Voltage Input

Functions: Voltage Transformation + Power Distribution + Stable Power Supply

Cooling Method: Relies on the circulation of transformer oil for heat dissipation (typically ONAN)

Application Scenarios: Power grid distribution, industrial parks, substations, energy projects, etc.

Core Equipment Selection Requirements

Across Southeast Asia, the Middle East, Africa, and Latin America, demand for 35kV/0.4kV step-down transformers continues to rise, driven by industrial parks, grid upgrade projects, commercial developments, and renewable energy integration.

For most buyers, the selection criteria are consistent:

● High energy efficiency and low operating losses

● Long service life under continuous operation

● Compliance with international standards and certifications

● Stable outdoor performance with minimal maintenance requirements

The GUANGBIAN S13 Series (up to 2500kVA) is designed to meet these requirements. It adopts a copper winding structure and ONAN cooling system, providing reliable performance for 35kV applications. With IEC60076 compliance and standard Dyn11 vector group configuration, it is widely used by EPC contractors and system integrators across different markets, and is commonly included in 35kV/0.4kV transformer selection lists.

Technical Parameters

S13 Series 2500kVA Transformer — Complete Technical Datasheet:

The key specifications below align directly with common procurement requirements, and we also offer project-specific customization options upon request.

Core Advantages & Technical Highlights

Key Advantages

Lower Energy Losses

Compared with traditional S9 and S11 transformers, the S13 series reduces no-load loss by up to 30% and load loss by around 15%, helping lower operating costs in continuous-duty applications.

Cost-Effective for Long-Term Projects

For 24/7 industrial and utility operations, energy savings can significantly reduce lifecycle costs and improve return on investment over time.

100% Oxygen-Free Copper Windings

Both HV and LV windings use high-purity copper for better conductivity, improved thermal stability, and stronger short-circuit resistance.

Designed for Continuous Full-Load Operation

Suitable for demanding outdoor environments, the transformer maintains stable performance under continuous heavy-load conditions.

Long Service Life

Built with durable insulation materials and robust structural design to support reliable operation for 30 years or more.

Ideal for Industrial & Utility Transformer Procurement

Widely used in industrial plants, utility distribution systems, solar power projects, and infrastructure power networks.

Reliable ONAN Cooling for Low-Maintenance Operation

The ONAN (Oil Natural Air Natural) cooling design operates without auxiliary fans or pumps, reducing mechanical failure points and maintenance requirements. The sealed tank structure protects the transformer oil from outside air, helping slow oil aging and maintain stable performance over time. In real-world applications, many units can operate for years with minimal maintenance, making them well suited for remote substations, industrial power systems, and utility distribution projects.

Dyn11 Vector Group - Why It Actually Helps in the Field

The Dyn11 configuration suppresses 3rd harmonic currents and reduces neutral point shift - that's the kind of thing that shows up as instability in unbalanced loads at commercial and industrial sites. It also handles single-phase loading better, which makes a real difference when you're dealing with mixed load conditions. Protective relay coordination comes in cleaner with this vector group, adding a layer of safety to the overall power system setup.

Outdoor-Ready from the Ground Up

The tank and coating are built to withstand high temperature, humidity, salt air, and dust, ensuring stable operation in demanding conditions. Integrated lightning protection further enhances operational safety.

Suitable for outdoor substations, unmanned switch rooms, and remote installations, the GUANGBIAN S13-M 2500kVA 35kV Oil-Immersed Distribution Transformer requires no extra enclosure or shielding, making it a practical choice for outdoor power distribution projects.

As a China-based transformer factory and established transformer manufacture, GUANGBIAN supplies units across Southeast Asia, the Middle East, Africa, and Latin America - with IEC60076 compliance and customization options available for project-specific requirements. Reach out for datasheets or technical discussions.

Our Factory

Sheet metal workshop

Foil winding workshop

Winding workshop

Winding oven workshop

Transformer assembly workshop

Transformer commissioning workshop

FAQ

1. What is a 2500kVA 35kV oil-immersed distribution transformer used for?

It is used to step down 35kV medium-high voltage power to lower distribution voltages for industrial plants, utility substations, renewable energy systems, and large infrastructure projects.

2. What does 2500kVA mean?

2500kVA refers to the transformer’s rated capacity, indicating it can handle large-scale electrical loads suitable for industrial and utility-level power distribution.

3. Why is oil used in this type of transformer?

Insulating oil provides both electrical insulation and heat dissipation, helping improve cooling performance and extending service life.

4. What are the advantages of a 35kV rating?

35kV is a common distribution voltage level in medium-high voltage networks, offering efficient long-distance transmission with reduced power loss.

5. What cooling method is typically used?

Most units use ONAN (Oil Natural Air Natural) cooling, which relies on natural oil circulation and air cooling without auxiliary equipment.

6. Where is this transformer commonly installed?

It is widely used in outdoor substations, industrial parks, mining operations, solar and wind power plants, and grid expansion projects.

7. How long is the service life?

With proper design and maintenance, oil-immersed distribution transformers typically operate for 25–30 years or more.

8. What are the key maintenance requirements?

Routine oil inspection, temperature monitoring, and periodic electrical testing are the main maintenance tasks to ensure stable long-term operation.