Introduction
A three phase transformer is one of the most widely used electrical transformers in industrial power distribution systems. It is designed to transfer electrical energy between three-phase power circuits while changing voltage levels efficiently and safely.
Three phase transformers are commonly used in:
- Industrial factories
- Commercial buildings
- Utility substations
- Solar power plants
- Wind energy projects
- Mining facilities
- Data centers
- Manufacturing plants
Compared with single phase transformers, a three phase transformer provides higher power capacity, improved efficiency, and better load balance, making it the preferred solution for medium voltage and high-power electrical systems.
As an experienced three phase transformer manufacturer, EverNew Transformer provides customized transformer solutions from 15 kVA to 500 MVA, including:
- Three phase dry type transformers
- Three phase oil immersed transformers
- Distribution transformers
- Power transformers
- Pad mounted transformers
What Is a Three Phase Transformer?
A three phase transformer is an electrical transformer designed for three-phase alternating current (AC) systems.
Unlike a single phase transformer, which operates with one alternating voltage waveform, a three-phase transformer uses three separate phases with a 120-degree phase difference.
The three phases provide:
- Higher power transmission efficiency
- Reduced conductor size
- Better motor performance
- More stable industrial power supply
A typical three phase transformer contains:
- Three primary windings
- Three secondary windings
- Magnetic core
- Insulation system
- Cooling system
- Transformer enclosure
How Does a Three Phase Transformer Work?
The operating principle of a three phase transformer is based on electromagnetic induction.
When AC voltage is applied to the primary winding, it creates alternating magnetic flux inside the transformer core. This magnetic flux induces voltage in the secondary winding.
The voltage conversion ratio depends on the relationship between winding turns:
Voltage Ratio = Primary Turns / Secondary Turns
For example:
Step Down Transformer
Input:
13.8kV
Output:
480V
The transformer reduces medium voltage electricity to a usable low voltage level for industrial equipment.
Three Phase Transformer Types
Three phase transformers can be classified according to construction, insulation method, cooling system, and application.
1. Three Phase Dry Type Transformer
A three phase dry type transformer uses air as the cooling and insulation medium instead of transformer oil.
Dry type transformers are widely used where fire safety and environmental protection are important.
Advantages of Dry Type Transformer
High fire safety
No oil leakage risk
Low maintenance requirements
Suitable for indoor installation
Environmentally friendly
Common Applications
Three phase dry type transformers are commonly installed in:
Commercial buildings
Hospitals
Airports
Data centers
Industrial facilities
Shopping centers
Typical ratings:
| Capacity | Application |
|---|---|
| 15 kVA | Small commercial loads |
| 45 kVA | Industrial equipment |
| 75 kVA | Building power supply |
| 500 kVA | Factory distribution |
| 2500 kVA | Large industrial systems |
EverNew manufactures dry type transformers with:
- Copper winding
- Aluminum winding
- Cast resin insulation
- UL/CSA compliant designs
2. Three Phase Oil Immersed Transformer
A three phase oil immersed transformer uses insulating oil for cooling and electrical insulation.
Oil immersed transformers are commonly used for outdoor power distribution because they provide excellent heat dissipation and high capacity capability.
Advantages
- High power capacity
- Excellent cooling performance
- Long service life
- Suitable for outdoor applications
Applications
Common applications include:
- Utility substations
- Solar farms
- Wind farms
- Industrial plants
- Power transmission systems
Typical voltage ratings:
- 6kV
- 10kV
- 11kV
- 13.8kV
- 35kV
- 110kV
- 220kV
3. Three Phase Distribution Transformer
A three phase distribution transformer is designed to reduce medium voltage electricity to low voltage for end users.
Typical conversion:
11kV → 400V
13.8kV → 480V
35kV → 400V
Applications:
- Residential areas
- Commercial facilities
- Industrial factories
4. Three Phase Power Transformer
A three phase power transformer is used in high voltage transmission and substations.
Applications:
- Power plants
- Grid substations
- Renewable energy projects
Power range:
From several MVA to hundreds of MVA.
Three Phase Transformer Applications
Industrial Power Systems
Factories rely on three phase transformers to supply power for:
- Motors
- Compressors
- Pumps
- CNC machines
- Production lines
- Automation equipment
Industrial transformers usually require:
- High efficiency
- Continuous operation
- Strong overload capability
Commercial Buildings
Three phase transformers are commonly used in:
- Office buildings
- Hotels
- Shopping malls
- Airports
A common North American system:
480V → 208Y/120V
This voltage system is widely used for:
- Lighting
- HVAC systems
- Building equipment
Renewable Energy Projects
Solar and wind projects require transformers to increase voltage before grid connection.
Example:
Solar inverter:
800V
↓
Transformer:
0.8kV / 35kV
↓
Grid connection
Three Phase Transformer Voltage Ratings
Different countries use different voltage standards.
North America
Common voltages:
| Primary Voltage | Secondary Voltage |
|---|---|
| 480V | 208Y/120V |
| 600V | 347/600V |
| 13.8kV | 480V |
| 34.5kV | 480V |
International Markets
Common systems:
| Primary | Secondary |
|---|---|
| 10kV | 400V |
| 11kV | 415V |
| 20kV | 400V |
| 35kV | 400V |
EverNew transformers can be designed according to:
- IEC
- ANSI
- IEEE
- UL
- CSA
- CE
- GOST
How To Select A Three Phase Transformer?
Choosing the correct transformer requires evaluating several technical parameters.
1. Transformer Capacity (kVA)
The transformer capacity must match the electrical load.
Common sizes:
- 15 kVA
- 30 kVA
- 45 kVA
- 75 kVA
- 112.5 kVA
- 150 kVA
- 500 kVA
- 1000 kVA
- 2500 kVA
2. Input and Output Voltage
Example:
Commercial building:
Input:
480V Three Phase
Output:
208Y/120V Three Phase
3. Frequency
Common frequencies:
- 50Hz
- 60Hz
4. Transformer Cooling Method
Choose according to installation environment:
Indoor:
Dry Type Transformer
Outdoor:
Oil Immersed Transformer
5. Transformer Standards
International projects may require:
- UL certification
- CSA certification
- DOE efficiency
- IEC standards
- IEEE standards
Three Phase Transformer Manufacturer
Selecting a reliable three phase transformer manufacturer is important for ensuring safety, efficiency, and long service life.
A professional transformer supplier should provide:
✔ Engineering design support
✔ Factory testing
✔ International certifications
✔ Customized voltage solutions
✔ Export experience
Why Choose EverNew Transformer?
EverNew Transformer is a professional transformer manufacturer in China with more than 30 years of experience.
Our manufacturing capabilities include:
Product Range
- Distribution Transformer
- Dry Type Transformer
- Oil Immersed Transformer
- Pad Mounted Transformer
- Power Transformer
Technical Capability
Capacity:
15 kVA – 500 MVA
Voltage:
6kV – 500kV
Certifications
- UL
- CSA
- CE
- GOST
- ISO
We supply transformers for:
- USA
- Canada
- South America
- Europe
- Asia
- Africa
Three Phase Transformer FAQ
What is the difference between single phase and three phase transformer?
A single phase transformer is normally used for smaller loads, while a three phase transformer is designed for industrial and commercial power systems requiring higher capacity.
What is the most common three phase transformer voltage?
Common systems include:
- 480V
- 208Y/120V
- 400V
- 415V
- 13.8kV
- 35kV
How much does a three phase transformer cost?
The price depends on:
- Transformer capacity
- Voltage rating
- Copper or aluminum winding
- Cooling method
- Required standards
- Order quantity
How do I choose a three phase transformer size?
You should consider:
- Total connected load
- Starting current
- Future expansion
- Voltage requirements
- Efficiency requirements
Conclusion
A three phase transformer is an essential component in modern electrical power systems, providing efficient voltage conversion for industrial, commercial, and renewable energy applications.
Choosing the correct transformer requires careful evaluation of:
- Power capacity
- Voltage levels
- Cooling method
- Installation environment
- International standards
As a professional three phase transformer manufacturer, EverNew Transformer provides reliable transformer solutions worldwide with customized designs from low voltage distribution systems to high voltage power networks.
Contact EverNew Transformer today for your three phase transformer project.
