Step Down Oil Immersed Power Distribution Transformer

Our step down oil immersed power distribution transformer is engineered to convert medium or high-voltage electricity (such as 11kV, 22kV, or 33kV) into standardized low-voltage output (such as 400V or 230V) suitable for end-user consumption. This product is ideal for power distribution networks requiring reliable voltage regulation, high overload capacity, and long-term durability.

The transformer features a low-loss grain-oriented silicon steel core and high-conductivity copper windings, significantly reducing no-load and load losses. The oil-immersed cooling system ensures efficient heat dissipation, while the fully sealed structure prevents moisture ingress and oil oxidation, reducing maintenance requirements and extending operational life.

Product Feature And Application

Features

1. Meets or exceeds IEC, ANSI, GB, and SANS standards

2. Fully sealed structure with corrugated tank design

3. High overload capacity and thermal stability

4. Low noise operation and high efficiency

5. Compact design suitable for pole-mounted or ground-mounted installations

6. Robust short-circuit withstand capability

7. Easy installation and low maintenance

8. Long service life with lifetime service support

9. Available with multiple tapping ranges for voltage regulation

10. Environmentally friendly insulating oil options available

Q&A: Key step down oil immersed power distribution transformer Insights

Q: What is a Step Down Transformer?

A: A step down transformer is a type of electrical transformer that reduces high input voltage to a lower output voltage. It consists of more turns on the primary winding and fewer turns on the secondary winding. This type of power transformer is essential in power distribution systems to safely deliver usable voltage levels to industrial equipment, commercial buildings, and residential areas.

Q: What makes this step down transformer energy efficient?

A: Our transformer uses high-permeability cold-rolled grain-oriented silicon steel and optimized core joint structures, which significantly reduce hysteresis and eddy current losses. This results in lower no-load and load losses compared to conventional transformers, directly reducing operating costs.

Q: How does the oil-immersed cooling system improve performance?

A: The insulating oil serves both as a dielectric medium and a coolant. It efficiently transfers heat away from the core and windings to the tank surface, where it dissipates into the surrounding environment. This ensures stable operation even under continuous high-load or high-temperature conditions.

Q: Is this transformer suitable for outdoor use?

A: Yes. The fully sealed corrugated tank design protects internal components from moisture, dust, and corrosive environments. It is ideal for outdoor installations such as substations, industrial yards, and rural power distribution networks.

Main Application Scenarios

Industrial Facilities: Provides reliable low-voltage power for factories, processing plants, and heavy machinery.

Commercial Buildings: Used in shopping malls, office complexes, and hotels to step down medium voltage to safe levels.

Residential Power Distribution: Installed in community substations or pole-mounted configurations to supply households.

Renewable Energy Systems: Integrates with solar farms and wind power plants for voltage regulation and grid connection.

Infrastructure Projects: Suitable for airports, railways, hospitals, and data centers requiring high reliability.

Product Parameter (Specification)

Table: Step Down Oil Immersed Transformer – Typical Specifications (11kV / 0.4kV)

Oil Immersed vs Dry Type Transformer

Choose an oil-immersed transformer in the following situations: when outdoor installation is required; when higher energy efficiency is needed;when a higher overload capacity is required; when medium or large capacity is needed; or when seeking a cost-effective power distribution solution.

Choose a dry-type transformer in the following situations: when the transformer is installed indoors; when fire safety is critical;when the use of oil-based media is prohibited on-site; or when the project involves hospitals, shopping malls, data centers, or high-rise buildings.

Summary: Oil-immersed transformers are better suited for outdoor, industrial, and public grid power distribution applications. Dry-type transformers are better suited for indoor use and locations with strict fire safety requirements.

Production Details

Core Material and Process

The core is constructed using high-permeability cold-rolled grain-oriented silicon steel with a stepped lap joint design, minimizing no-load losses and reducing magnetizing current. The core is bound with semi-dry glass tape to ensure structural integrity and low noise.

Winding Structure

High-voltage and low-voltage windings are made from oxygen-free copper conductors. Low-voltage windings adopt a foil or helical structure with longitudinal oil ducts, enhancing mechanical strength and short-circuit withstand capability.

Insulation and Cooling System

High-quality mineral oil or environmentally friendly high-fire-point insulating fluid is used. The oil-paper insulation system undergoes vacuum drying and oil-filling processes to eliminate residual moisture and air, ensuring high dielectric strength and long-term reliability.

Tank and Sealing

The corrugated tank design provides thermal expansion compensation without the need for a conservator. The fully sealed structure prevents oil oxidation and moisture ingress, reducing maintenance frequency and extending oil life.

Standard equipment includes

1. Oil level gauge with low-level alarm

2. Pressure relief valve

3. Dial thermometer with alarm contacts

4. Optional gas relay for fault detection

Why Choose Lugao Step Down Transformer

Lugao step down oil immersed transformer is designed to reduce medium or high voltage, such as 11kV, 22kV, 33kV, to low voltage, such as 400V or 230V, for safe power distribution.

High Efficiency：Low-loss silicon steel core reduces no-load loss and saves energy.

Stable Performance：Copper windings and optimized structure ensure stable voltage output.

Strong Cooling Ability：Oil immersed cooling system provides excellent heat dissipation and supports long-time operation.

Fully Sealed Tank：Prevents moisture, dust, and oil oxidation, reducing maintenance.

High Short-Circuit Strength：Strong winding and clamping structure improve safety during grid faults.

Outdoor Use：Suitable for substations, factories, rural grids, commercial buildings, and renewable energy projects.

Custom Design Available：Voltage, capacity, vector group, tapping range, cooling method, and tank type can be customized.

Strict Testing Before Delivery：Each transformer is tested for voltage ratio, winding resistance, insulation, no-load loss, load loss, impedance, and oil leakage.

Lugao provides OEM and ODM transformer solutions with reliable quality, fast delivery, and professional technical support.

Product After-Sales Service

1. Free repair or replacement for quality issues caused by manufacturing defects within one year.

2. Damage caused by human error or force majeure (lightning strike, flooding, fire, etc.) is not covered under warranty.