Oil-immersed distribution transformer
Oil-immersed distribution transformers are among the most widely used and technically mature solutions in medium-voltage power distribution systems.
GE Transformer offers a complete range from 3.3kV to 38.5kV, serving utilities, power plants, industrial facilities, renewable energy projects, and commercial buildings.
Designed with high-grade silicon steel or amorphous alloy cores and manufactured using advanced vacuum drying and vacuum oil filling processes, our transformers ensure:
- Excellent insulation performance
- Stable overload capability
- Low operational losses
- 25+ years design service life
- Fully compliant with IEC 60076 and ANSI/IEEE C57 standards.
Oil-immersed distribution transformers
Oil-immersed distribution transformer Parameters
| No. | Item | Specification |
| 1 | Power Rating | 15-5000 kVA |
| 2 | Primary Voltage | 3.3KV,6KV,10KV,11KV,13.2KV,13.8 kV,15KV,20KV,33KV,35KV Class |
| 3 | Secondary Voltage | 480/277V, 400/230V, 380/220V, or customized |
| 4 | Phase | Three-phase |
| 5 | Cooling Type | ONAN or others |
| 6 | Core Material | High-efficiency silicon steel |
| 7 | Connection Group | Dyn11, Yyn0, Dyn5 |
| 8 | Winding Material | Copper/Aluminum |
| 9 | Frequency | 50/60Hz |
| 10 | Insulation | Mineral oil |
| 11 | Tap Changer | ±2 x 2.5% Off-Circuit Tap Changer (OCTC) |
| 12 | Short-circuit impedance | 4-6% |
| 13 | Temperature Rise | 60-65°C |
| 14 | Noise Level | ≤ 60 dB at 1 meter |
| 15 | Enclosure | Hermetically sealed steel tank, weatherproof for indoor and outdoor use |
| 16 | Altitude | ≤1,000m or Customized |
| 17 | Ambient Temperature Range | -30°C to +50°C |
| 18 | Accessories | Conservator tank, oil level indicator, gas relay, pressure relief valve, etc. |
| 19 | Standards Compliance | IEC60076，ANSI C57, IEEE, UL, CSA |
| 20 | Applications | Commercial and institutional buildings, industrial facilities, oil & gas, solar and wind energy, utility grid connections, data centers, and It can also be used in coastal islands and high-altitude regions. |
| 21 | Transport & Installation | Lifting lugs, skid base, galvanized fittings |
| 22 | Warranty | Typically one year, depending on the client’s specific needs |
| 23 | Delivery Time | Generally, it is 20-30 days. It is according to the quantity. |
| 24 | Min. order quantity | ≧ 1 set |
Quality Control & Testing
GE Transformer has established a comprehensive quality control system, monitoring the entire process from raw materials through to final factory testing.
Raw Material Inspection
- Silicon Steel Sheet Core Loss Testing
- Copper Wire Resistance Testing
- Insulating Oil Breakdown Voltage Testing
Production Control
- Core Stacking Precision Inspection
- Winding Inter-turn Insulation Testing
- Vacuum Drying Process Monitoring
Factory Testing
- Voltage Ratio Testing
- Winding Resistance Measurement
- Insulation Resistance Measurement
- Short-Circuit Impedance Testing
- Applied Voltage Withstand Testing
- Induced Voltage Withstand Testing
- No-Load Loss and Load Loss Testing
- Temperature Rise Testing
- Noise Testing
Transformer Oil Dielectric Strength Testing
Oil Tank Leakage Testing
Why Choose GE Transformer
Quality Control: Quality is a core value of GE Transformer. We conduct Factory Acceptance Testing (FAT), type testing, and third-party inspections to ensure superior quality. We strictly adhere to the ISO 9001 quality management system, committed to providing our customers with the highest quality products.
Professional Team: Our team comprises highly skilled professionals dedicated to responding quickly to customer needs. All GE Transformer team members receive systematic training and continuously improve their capabilities through rigorous quality standards and practices. Our commitment to customer service, product innovation, engineering excellence, and social and environmental responsibility makes us a trusted partner in the global power industry.
Certifications
- ISO9001：2015
- CE Certifications:
- UL Certifications:
- CSA Certification:
- CNAS Certification:
Competitive Market Pricing:Leveraging years of industry experience, GE Transformer integrates high-quality resources across R&D, production, procurement, transportation, and service, achieving effective cost control.
Fast Delivery: Strong production capacity, multiple freight partners, and a professional pre-sales and after-sales team, adhering to the “customer first” philosophy, provide customers with fast delivery and usage services.
Buying Notice:
Transformer Unit:
Rated capacity, primary and secondary voltages, winding material, tap range, frequency, connection group, impedance, temperature rise, no-load and load losses.
Accessories:
Conservator tank, oil level indicator, gas relay, pressure relief valve, etc.
Others:
Altitude, cooling method, noise level, insulating oil, etc.
FAQ
What is the difference between oil-immersed and dry-type transformers?
Oil-immersed transformers use insulating oil for cooling and insulation, offering superior heat dissipation and overload capacity. They are suitable for outdoor and medium-to-high capacity applications.
Dry-type transformers use air or resin insulation and are typically installed indoors where fire safety is a priority.
In general, oil-immersed transformers offer better performance in higher capacities and cost efficiency.
What is the service life of an oil-immersed distribution transformer?
Under normal operating conditions and proper maintenance, the design service life is typically 25–30 years.
With proper oil management and load control, the operational life can be extended even further.
How do I select the correct transformer capacity?
Transformer capacity should be determined based on total load demand, load type (inductive/resistive), future expansion plans, and required overload capacity.
A 10–20% capacity margin is generally recommended for stable long-term operation.
Can voltage and technical specifications be customized?
Yes. GE Transformer provides customized solutions including voltage ratings, capacity, impedance, tap range, cooling methods, and special environmental designs.
Products can be designed according to IEC or IEEE standards.
Are your transformers suitable for high altitude or high temperature environments?
Yes. Special designs can be implemented for high altitude, high temperature, or humid environments, including enhanced cooling and adjusted insulation levels.
What is the typical delivery time?
Standard models typically require 15-20 days, depending on capacity, quantity, and customization requirements.