Sub-Station Transformer
Sub-Station / Power Transformer
Unitrans Power LLP manufactures a complete range of oil-immersed sub-station and power transformers, engineered and tested in compliance with IS, IEC, ANSI, IEEE, NEMA, CSA, and ISO standards. Designed for high efficiency, reliability, and long service life, these transformers are ideal for utilities, industrial plants, and infrastructure networks. Available in ratings up to 20 MVA and voltage classes up to 66 kV, they ensure stable and dependable power delivery across critical applications.
Built with high-grade materials, precision-engineered windings, and robust tank construction, our transformers deliver low losses, superior performance, and long-term durability. Optional On-Load Tap Changers (OLTC) and Off-Circuit Tap Switches provide flexibility for step-up and step-down applications, making them suitable for a wide range of substation requirements.
Design & Construction Features
- Robust, leak-proof tank construction for safe operation
- Precision-engineered windings for low losses and high efficiency
- High-grade insulation for long-term thermal and dielectric performance
- Designed for On-Load Tap Changer (OLTC) or Off-Circuit Tap Switch options
- Attention to safety, environmental compliance, and global quality standards
Testing
All sub-station transformers undergo comprehensive testing in accordance with:
IS, IEC, ANSI, IEEE, NEMA, and CSA standards.
- Routine and type tests for performance and safety
- Factory Acceptance Tests (FAT) – available virtual or in-person
- Additional tests available upon request
Unitrans Power LLP ensures that every sub-station transformer delivers safe, reliable, and efficient power, making it the backbone of critical energy infrastructure worldwide.
Technical Specifications
| Parameter | Details |
| Capacity | Up to 20 MVA |
| Voltage Class | Up to 66 kV |
| Frequency | 50 Hz or 60 Hz |
| Cooling Class | ONAN, ONAF, OFAF, or OFWF |
| Temperature Rise | 55°C / 65°C |
| Insulating Oil | Mineral Oil, FR3, or Ester Oil |
| Winding Material | Aluminium or Copper |
| Standards | IS, IEC, ANSI, IEEE, NEMA, CSA, ISO |
