Voltage Ratio = Primary Turns / Secondary Turns
For example:
Snižující transformátor
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
Vysoká požární bezpečnost
No oil leakage risk
Nízké nároky na údržbu
Vhodné pro instalaci v interiéru
Environmentally friendly
Common Applications
Three phase dry type transformers are commonly installed in:
Komerční budovy
Nemocnice
Letiště
Datová centra
Průmyslová zařízení
Shopping centers
Typical ratings:
| Kapacita | Aplikace |
|---|---|
| 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.
Výhody
- High power capacity
- Excellent cooling performance
- Dlouhá životnost
- Suitable for outdoor applications
Aplikace
Mezi běžné oblasti použití patří:
- Rozvodny veřejných služeb
- Solární farmy
- Větrné farmy
- Průmyslové závody
- Power transmission systems
Typical voltage ratings:
- 6kV
- 10kV
- 11kV
- 13.8kV
- 35 kV
- 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
Aplikace:
- Obytné oblasti
- Commercial facilities
- Průmyslové závody
4. Three Phase Power Transformer
A třífázový síťový transformátor is used in high voltage transmission and substations.
Aplikace:
- Power plants
- Grid substations
- Projekty v oblasti obnovitelných zdrojů energie
Rozsah výkonu:
From several MVA to hundreds of MVA.

Three Phase Transformer Applications
Průmyslové energetické systémy
Factories rely on three phase transformers to supply power for:
- Motory
- Compressors
- Pumps
- CNC machines
- Production lines
- Automation equipment
Industrial transformers usually require:
- High efficiency
- Continuous operation
- Strong overload capability
Komerční budovy
Three phase transformers are commonly used in:
- Kancelářské budovy
- Hotels
- Nákupní centra
- Letiště
A common North American system:
480V → 208Y/120V
This voltage system is widely used for:
- Lighting
- Systémy vytápění, ventilace a klimatizace
- Building equipment
Projekty obnovitelných zdrojů energie
Solar and wind projects require transformers to increase voltage before grid connection.
Příklad:
Solar inverter:
800V
↓
Transformer:
0.8kV / 35kV
↓
Grid connection
Three Phase Transformer Voltage Ratings
Different countries use different voltage standards.
Severní Amerika
Common voltages:
| Primární napětí | Sekundární napětí |
|---|---|
| 480V | 208Y/120V |
| 600V | 347/600V |
| 13.8kV | 480V |
| 34,5 kV | 480V |
International Markets
Common systems:
| Primary | Secondary |
|---|---|
| 10kV | 400V |
| 11kV | 415V |
| 20kV | 400V |
| 35 kV | 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
Příklad:
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:
Suchý typ transformátoru
Outdoor:
Transformátor ponořený do oleje
5. Transformer Standards
Mezinárodní projekty mohou vyžadovat:
- UL certification
- CSA certification
- DOE efficiency
- Normy IEC
- Normy 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
Proč si vybrat transformátor EverNew?
EverNew Transformer is a professional transformer manufacturer in China with more than 30 years of experience.
Mezi naše výrobní kapacity patří:
Product Range
- Distribuční transformátor
- Suchý typ transformátoru
- Transformátor ponořený do oleje
- Transformátor namontovaný na podložce
- Výkonový transformátor
Technical Capability
Kapacita:
15 kVA – 500 MVA
Napětí:
6kV – 500kV
Certifikace
- UL
- CSA
- CE
- GOST
- ISO
We supply transformers for:
- USA
- Kanada
- Jižní Amerika
- Evropa
- Asia
- Afrika
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
- 35 kV
How much does a three phase transformer cost?
The price depends on:
- Transformer capacity
- Voltage rating
- Copper or aluminum winding
- Způsob chlazení
- 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
Závěr
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
- Způsob chlazení
- Installation environment
- Mezinárodní normy
Jako profesionál 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.


