Voltage Ratio = Primary Turns / Secondary Turns
For example:
Transformador abaixador
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
Elevado nível de segurança contra incêndios
Sem risco de fuga de óleo
Baixa necessidade de manutenção
Adequado para instalação em interiores
Respeitador do ambiente
Common Applications
Three phase dry type transformers are commonly installed in:
Edifícios comerciais
Hospitais
Aeroportos
Centros de dados
Instalações industriais
Shopping centers
Typical ratings:
| Capacidade | Aplicação |
|---|---|
| 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.
Vantagens
- High power capacity
- Excellent cooling performance
- Longa vida útil
- Suitable for outdoor applications
Aplicações
Entre as aplicações mais comuns contam-se:
- Subestações de serviços públicos
- Parques solares
- Parques eólicos
- Instalações industriais
- 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
Aplicações:
- Zonas residenciais
- Commercial facilities
- Fábricas industriais
4. Three Phase Power Transformer
A three phase power transformer is used in high voltage transmission and substations.
Aplicações:
- Power plants
- Grid substations
- Projectos de energias renováveis
Gama de potências:
From several MVA to hundreds of MVA.

Three Phase Transformer Applications
Sistemas de energia industrial
Factories rely on three phase transformers to supply power for:
- Motores
- Compressors
- Pumps
- CNC machines
- Production lines
- Automation equipment
Industrial transformers usually require:
- High efficiency
- Funcionamento contínuo
- Strong overload capability
Edifícios comerciais
Three phase transformers are commonly used in:
- Edifícios de escritórios
- Hotels
- Centros comerciais
- Aeroportos
A common North American system:
480V → 208Y/120V
This voltage system is widely used for:
- Lighting
- Sistemas de climatização
- Building equipment
Projectos de energias renováveis
Solar and wind projects require transformers to increase voltage before grid connection.
Exemplo:
Solar inverter:
800V
↓
Transformer:
0.8kV / 35kV
↓
Grid connection
Three Phase Transformer Voltage Ratings
Different countries use different voltage standards.
América do Norte
Common voltages:
| Tensão primária | Tensão secundária |
|---|---|
| 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:
- CEI
- 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
Exemplo:
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:
Transformador de tipo seco
Outdoor:
Transformador imerso em óleo
5. Transformer Standards
Os projetos internacionais podem exigir:
- UL certification
- CSA certification
- DOE efficiency
- Normas CEI
- Normas do IEEE

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
Por que escolher o transformador EverNew?
EverNew Transformer is a professional transformer manufacturer in China with more than 30 years of experience.
Our manufacturing capabilities include:
Product Range
- Transformador de distribuição
- Transformador de tipo seco
- Transformador imerso em óleo
- Transformador montado na base
- Transformador de potência
Technical Capability
Capacidade:
15 kVA – 500 MVA
Tensão:
6kV – 500kV
Certificações
- UL
- CSA
- CE
- GOST
- ISO
We supply transformers for:
- EUA
- Canadá
- América do Sul
- Europa
- Ásia
- África
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?
O preço depende de:
- Transformer capacity
- Voltage rating
- Copper or aluminum winding
- Método de arrefecimento
- Normas exigidas
- 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
Conclusão
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
- Método de arrefecimento
- Installation environment
- International standards
Como profissional 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.


