Medium Voltage Electrical Substation Transformer – 33/11kV, 2.5MVA to 6.3MVA, Copper Winding, Oil Type
Jan 21, 2026
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Medium Voltage Substation Transformer – 33/11kV, 2.5MVA to 6.3MVA
This 33/11kV medium voltage (MV) substation transformer is engineered for stable and efficient voltage conversion in regional power grids and distribution networks. With a rated capacity ranging from 2.5MVA to 6.3MVA, it features a 33kV delta-connected primary and an 11kV grounded wye-connected secondary. Constructed with copper windings, a premium silicon steel core and oil-immersed insulation, it ensures low losses, high thermal stability and reliable long-term performance in both 50Hz and 60Hz systems.
Every substation transformer is manufactured at GNEE's modern facilities and fully complies with ANSI, IEEE, IEC and GOST standards. Designed for outdoor installation, it is equipped with a hermetically sealed oil tank, Buchholz relay, pressure relief valve, temperature sensors and an oil level indicator. Housed in a weatherproof enclosure, the transformer guarantees safe operation even in harsh climatic conditions, making it suitable for utility and industrial applications across the Americas and Spanish-speaking regions.
As a leading Chinese manufacturer and global supplier, GNEE provides wholesale and OEM solutions for power substation transformers to markets including the United States, Canada, Mexico, Brazil, Argentina, Peru, Bolivia, Guyana, Panama and Spain. With fast production cycles, ample supply capacity and comprehensive technical support, we help customers reduce costs while ensuring grid stability and operational safety.
Learn More: 500 kVA 34.5kV Three-Phase Oil-Immersed Under-Mounted Substation Transformer
✅ Overview of Medium Voltage Substation Transformer
Rated from 2.5 MVA to 6.3 MVA at 33/11 kV, this three-phase oil-immersed transformer is engineered for efficient step-down voltage conversion and power distribution in industrial, utility and commercial substations. Featuring copper windings and mineral oil insulation, it delivers reliable, stable and high-efficiency performance, and is suitable for harsh outdoor environments. Widely deployed across North and South America, it meets the growing demand for durable medium voltage transformers in smart grid, renewable energy and heavy industrial applications.
✅ Technical Specifications of Medium Voltage Substation Transformer
Standard configurations include oil-air cooling, a ±5% tap changer (2.5% step, operable on-load or off-load), a Dyn11 vector group, a high-quality silicon steel core for loss reduction, and copper windings for optimal electrical conductivity. The insulation and tank design comply with IEC 60076, ANSI C57, IEEE, UL and CSA standards. These transformers meet the US Department of Energy (DOE) 2016 energy efficiency regulations and are engineered for long service life and low maintenance.
✅ Current Ratings of Medium Voltage Substation Transformer
With a 33 kV primary and 11 kV secondary, these transformers deliver a stable output current, ideal for applications such as high-power motor loads, commercial buildings, mining operations and renewable energy power plants. Copper windings ensure high current-carrying capacity and minimal losses, enabling efficient load handling and superior thermal stability.
✅ Dimensions of Medium Voltage Substation Transformer Typical Dimensions: 2200 mm (L) × 1400 mm (W) × 1800 mm (H), optimized for installation in urban substations and industrial facilities. Its compact design allows for easy integration with existing infrastructure, and custom dimensions are available upon request.
✅ Weight of Medium Voltage Substation Transformer
Depending on capacity and design features, the weight ranges from 3500 kg to 5500 kg. This impacts transportation, handling and foundation requirements, with heavier units typically offering higher mechanical strength and overload capacity.
✅ Enclosure of Medium Voltage Substation TransformerEquipped with a fully sealed, corrosion-resistant steel tank coated with a UV-protective finish. The standard protection class is IP23, with IP54 or higher ratings available as an option for harsher environments. The enclosure effectively protects against moisture, dust, rodents and severe weather conditions.
✅ Installation of Medium Voltage Substation Transformer
GNEE provides comprehensive installation support, including guidance for site preparation, grounding, pad construction and cable termination. All units are factory-tested, oil-filled and sealed for plug-and-play operation, and are compatible with both loop and radial feeder configurations.
✅ Windings of Medium Voltage Substation Transformer
Copper windings come as standard, offering excellent electrical conductivity and heat resistance. Aluminum windings are also available to meet the cost requirements of different customers. All windings undergo vacuum drying, resin impregnation and heat treatment to ensure durability.
✅ Efficiency of Medium Voltage Substation Transformer
Designed to comply with US DOE 2016 and CSA C802.1 standards, the product features premium silicon steel core laminations and an optimized winding geometry, resulting in extremely low no-load and load losses. Higher efficiency reduces operational costs and carbon emissions.
✅ Certifications of Medium Voltage Substation Transformer
Compliant with IEC 60076, ANSI C57, IEEE C57, UL, CSA and NEMA standards. Every unit undergoes routine tests, type tests and special tests, with relevant documentation provided to meet export compliance and engineering certification requirements.
Learn More: Electrical Power Transformers: Definition, Types, and Applications
✅ Applications of Medium Voltage Substation Transformer
Suitable for utility substations, industrial power distribution, commercial facilities, solar and wind farms, and mining operations across North and South America. Engineered to adapt to a variety of load profiles and environmental conditions.
✅ Voltage and Tap Options of Medium Voltage Substation Transformer
The standard primary voltage is 33 kV, adjustable from 6 kV to 35 kV. The secondary voltage is 11 kV, customizable upon request. The tap changer allows for ±5% regulation in 2.5% steps, with the option of on-load or off-load operation.
✅ Medium Voltage Substation Transformer for Sale
GNEE keeps oil-immersed transformers of 2.5 MVA to 6.3 MVA, 33/11 kV in stock for export to North, Central and South America. We offer highly competitive pricing, fast delivery lead times (30-45 days) and flexible OEM/ODM services.
✅ Pricing of Medium Voltage Substation Transformer
Factory prices range from US$18,000 to US$45,000, subject to configuration, certifications and shipping methods. Please contact us for a custom quote on CIF terms to Houston, Los Angeles, Panama City, Buenos Aires, Lima and other major ports.
✅ Medium Voltage Substation Transformer Manufacturers (USA, China, Global)
GNEE is a leading Chinese manufacturer supplying oil-immersed transformers compliant with UL certification and CSA standards for the American market. We offer flexible minimum order quantities, fast delivery speeds and comprehensive customization services to meet customers' specific technical and regulatory requirements.
✅ Wholesale Supply of Medium Voltage Substation TransformerWe support bulk orders for contractors, distributors and government bidding projects. Our production capacity ensures OEM brand customization, full standard compliance and door-to-door logistics services. In addition, we supply transformers of other specifications such as 500 kVA, 1500 kVA and 100,000 kVA.
Learn More: 600 kVA 33kV to 11kV Oil-Immersed Substation Transformer – Copper Windings
Why Choose GNEE's Medium Voltage Substation Transformer – 33/11kV, 2.5MVA to 6.3MVA?
GNEE's medium voltage substation transformers, rated from 2.5MVA to 6.3MVA at 33/11kV, are engineered for reliable power distribution in commercial, industrial and utility networks across North and South America. Featuring copper windings and oil-immersed cooling, these transformers deliver efficient voltage step-down while ensuring operational safety and durability.
Every unit is purpose-built to withstand harsh outdoor environments, with a rugged weatherproof enclosure and an internally sealed oil tank filled with eco-friendly insulating oil. This construction effectively resists severe weather, contaminants and mechanical impact, ensuring an extended service life for the equipment. Whether serving utility substations, industrial parks, renewable energy projects or large commercial facilities,GNEE's 33/11kV, 2.5MVA to 6.3MVA oil-immersed transformers provide a reliable, efficient and customizable solution for your medium voltage power distribution needs.
Contact us now for pricing, inventory availability, or a custom quote tailored to your substation transformer project.
33/11kV Medium Voltage Electrical Substation Transformer Technical Specs
| No. | Specification Item | Details | Notes/Remarks |
|---|---|---|---|
| 1 | Product Type | Oil-Immersed Medium Voltage Substation Transformer | Designed for electrical substations |
| 2 | Rated Capacity | 2.5 MVA – 6.3 MVA | Customizable within this power range |
| 3 | Phase | Three-Phase | Standard for utility distribution |
| 4 | Frequency | 50 Hz (60 Hz optional) | Common in Americas |
| 5 | Primary Voltage (High Voltage) | 33 kV | Customizable from 6 kV to 35 kV |
| 6 | Secondary Voltage (Low Voltage) | 11 kV | Other LV voltages customizable |
| 7 | HV Winding Connection | Delta (Δ) | Optional configurations available |
| 8 | LV Winding Connection | Wye (Y) with grounded neutral | Preferred for safety and stability |
| 9 | Vector Group | Dyn11 | Customizable |
| 10 | Tap Changer | ±5% range, 2.5% steps | Off-load or on-load options |
| 11 | No-load Loss | Approx. 1.5 kW | Energy efficient design |
| 12 | Load Loss (at 75°C) | Approx. 12 kW | Low loss technology |
| 13 | Short Circuit Impedance | 6% ±10% | Adjustable based on system requirements |
| 14 | Insulation Level HV Side | BIL 150 kV | Power frequency withstand 70 kV |
| 15 | Insulation Level LV Side | BIL 30 kV | Power frequency withstand 10 kV |
| 16 | Insulation Class | Class A or Class B | Optional |
| 17 | Max Temperature Rise | 65°C standard / 55°C low loss | Relative to ambient temperature |
| 18 | Altitude Rating | Up to 1000 meters | Derating required for higher altitudes |
| 19 | Ambient Operating Temperature | -40°C to +50°C | Special designs available |
| 20 | Cooling Method | ONAN (Oil Natural Air Natural) | ONAF forced cooling optional |
| 21 | Short Circuit Duration | 2 seconds | Designed for transient faults |
| 22 | Noise Level | ≤ 55 dB at 1 meter | Meets NEMA TR1 and IEC 60076 standards |
| 23 | Core Construction | Step-lap laminated core | High-grade silicon steel |
| 24 | Winding Material | Copper (standard), Aluminum (optional) | Superior conductivity and reliability |
| 25 | Tank Type | Fully sealed steel tank | Conservator tank optional |
| 26 | Transformer Oil | Mineral oil IEC 60296 standard | Eco-friendly options available |
| 27 | Protection Rating | IP00 standard, IP23 optional | Suitable for indoor/outdoor use |
| 28 | Surface Finish | Sandblasting + primer + topcoat painting | Corrosion-resistant coating |
| 29 | Standard Accessories | Pressure relief valve, oil level gauge, thermometer, drain valve, grounding terminals | Complete standard configuration |
| 30 | Protection Devices | Buchholz relay (optional), pressure relief, temperature alarms | Customizable |
| 31 | Monitoring Options | Optional IoT smart monitoring (temperature, humidity, load) | Enables predictive maintenance |
| 32 | Termination Type | Cable box or porcelain bushings | Flexible connection options |
| 33 | Cooling Radiators | Bolted or welded type | Designed for efficient heat dissipation |
| 34 | Standards Compliance | IEC 60076, ANSI C57, IEEE C57, CSA C88, GOST | Certification upon request |
| 35 | Testing | Routine, type, special tests | 100% inspection before shipment |
| 36 | Certifications | CE, UL, CSA, CUL, GOST | Market-specific certification |
| 37 | Dimensions (approx.) | 2200 mm (L) × 1400 mm (W) × 1800 mm (H) | Subject to final design |
| 38 | Weight (approx., including oil) | 4000 kg | – |