10kV Oil Immersed Transformer
The 10kV Oil Immersed Transformer is a high-performance, three-phase distribution transformer engineered for reliable medium-voltage power conversion in AC 50/60Hz systems. Featuring a fully sealed corrugated tank design, it eliminates the need for an oil conservator while providing excellent moisture resistance and extended service life. This transformer excels in energy savings, with up to 30% lower no-load losses compared to older models, making it ideal for modern grid upgrades and sustainable power distribution.
- Primary Voltage Ratings 34.5-19.92/13.8-7.957, 24.94, 26.25, 33 or others
- Secondary Voltage Ratings 480/277V, 400/230V, 380/220V or customized
- H.V. Tap Range ± 2×2.5% HV taps or others
- Type Oil immersed distribution transformer
- BIL 10 kV
- Standards IEEE, ANSI, NEMA, IEC, CE
- Application industrial parks and factories, rural power grid
- Power Rating 30kVA - 5000kVA
- Certificate UL, CESI, IEEE
- Cooling Method ONAN, ONAN/ONAF, KNAN, KNAN/KNAF
- Oil Mineral Oil or FR3
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
10kV Oil Immersed Transformer
Technical Specifications
Accessories
| Rated Power | 30kVA - 5000kVA | |
| Rating Primary Voltage | 2.4 - 34.5kV | |
| Secondary Voltage | 480/277V 400/230V 380/220V Customized |
|
| Frequency | 50/60Hz | |
| Vector Group | Dyn11, Yyn0, Dyn5 | |
| Winding Material | Aluminum/Copper | |
| Efficiency | As IEEE, Doe 2016, CAS Std or Customized | |
| Impedance Voltage | Nominal 2% or Customized 1.1 - 5.75% | |
| Altitude | ≤1,000m or Customized | |
| Color | ANSI 70 Light gray/Munsell 7GY3.29/1.5 or customized, etc | |
| Tank material | Mild Steel, 304 Stainless Steel | |
| Insulating Oil Weight | 850 kg | |
| Total Weight | 5000 kg | |
| Outline Dimensions（L×W×H）in. | 2650 × 1650 × 2450（mm) | |
| HV Bushing |
| LV Bushing |
| Tap changer |
| Oil level gauge |
| Oil temperature indicator |
| Pressure relief device |
| Pressure vacuum gauge |
| Lifting hook for complete transformer |
| Name plate |
| Radiators |
| Oil upper filtering valve |
| Oil drain valve with 3/8" sampler |
Customization Optional
10kV Oil Immersed Transformer
Our 10kV oil immersed transformers offer extensive customization to match specific project requirements, voltage needs, and environmental conditions. Customers can select rated capacities from 30kVA to 4000kVA, with primary voltages of 10kV (or 6kV/6.3kV/6.6kV options) and secondary voltages including 0.4kV, 0.433kV, or custom low-voltage configurations. Tap changers are available as off-circuit (no-excitation) or on-load voltage regulation for dynamic grid stability. Core materials include high-permeability grain-oriented silicon steel or amorphous metal for ultra-low no-load losses, while windings can be crafted from copper or aluminum to optimize cost and performance. Further personalization includes cooling enhancements like additional radiators for extreme ambient temperatures (-30°C to +50°C), special insulation oils (mineral or eco-friendly variants) for fire-prone or sensitive areas, and enclosure upgrades such as anti-corrosion coatings, seismic reinforcements, or IP-rated protection for harsh outdoor/indoor installations.
Accessories like conservators (if required), Buchholz relays, oil temperature indicators, winding temperature gauges, and smart monitoring systems (IoT-enabled for real-time data) can be integrated. We support vector groups (Dyn11, Yyn0, etc.), frequency adaptations (50Hz/60Hz), and compliance with global standards (IEC, IEEE, ANSI). Short-circuit impedance, efficiency levels, and noise reduction can be tailored to meet utility or industrial specifications, ensuring seamless integration into substations, renewable setups, or mining operations. Our engineering team collaborates closely to deliver bespoke solutions that enhance energy efficiency, reduce lifecycle costs, and align with regional regulations.
Packing and Shipping
10kV Oil Immersed Transformer
Careful packing and secure shipping are critical for safeguarding the integrity of 10kV oil immersed transformers during global transport. Each unit undergoes thorough pre-packing inspection to confirm no leaks, secure components, and proper sealing of all openings. The transformer tank is typically shipped filled with insulating oil to maintain positive pressure (0.01-0.03 MPa) and prevent moisture ingress, especially for units under 80 tons. For larger capacities, oil may be partially drained or fully removed to comply with weight limits, with separate sealed drums for on-site refilling. Radiators, bushings, conservators (if applicable), and control cabinets are detached and individually protected with foam padding, shrink-wrap, and moisture-resistant liners.
Export-grade packaging employs robust wooden crates or steel frames compliant with ISPM-15 standards, featuring custom blocking, bracing, and shock-absorbing materials to withstand vibrations, impacts, and tilting. Desiccant packs, rust inhibitors, and humidity indicators are included to monitor conditions. Shock recorders and tilt indicators are attached to log any excessive movement, ensuring accountability. For sea freight—common for international shipments—transformers are secured on flat-rack containers, open-top containers, or RoRo vessels with salt-fog-resistant coatings and weatherproof sheathing.
Documentation accompanies every shipment, including packing lists, commercial invoices, certificates of origin, test reports, installation manuals, lifting diagrams, and bills of lading. Customs HS codes, export permits, and oil handling declarations are prepared to facilitate smooth clearance. Upon arrival, buyers receive guidance for inspection, storage (avoid direct sunlight, maintain positive pressure if oil-filled), and professional unloading using cranes at marked lift points.
We coordinate multimodal logistics—road to port, then ocean or rail—tailored to destination constraints, offering optional services like on-site supervision, oil processing, and commissioning. This comprehensive approach minimizes risks, preserves transformer performance, and ensures timely delivery worldwide.
Export-grade packaging employs robust wooden crates or steel frames compliant with ISPM-15 standards, featuring custom blocking, bracing, and shock-absorbing materials to withstand vibrations, impacts, and tilting. Desiccant packs, rust inhibitors, and humidity indicators are included to monitor conditions. Shock recorders and tilt indicators are attached to log any excessive movement, ensuring accountability. For sea freight—common for international shipments—transformers are secured on flat-rack containers, open-top containers, or RoRo vessels with salt-fog-resistant coatings and weatherproof sheathing.
Documentation accompanies every shipment, including packing lists, commercial invoices, certificates of origin, test reports, installation manuals, lifting diagrams, and bills of lading. Customs HS codes, export permits, and oil handling declarations are prepared to facilitate smooth clearance. Upon arrival, buyers receive guidance for inspection, storage (avoid direct sunlight, maintain positive pressure if oil-filled), and professional unloading using cranes at marked lift points.
We coordinate multimodal logistics—road to port, then ocean or rail—tailored to destination constraints, offering optional services like on-site supervision, oil processing, and commissioning. This comprehensive approach minimizes risks, preserves transformer performance, and ensures timely delivery worldwide.
32
32 years of industry experience
Manufacturer Test
10kV Oil Immersed Transformer
Progress Test
During core production, the progress test includes silicon steel sheet inspection for burr-free edges, grain orientation and stacking quality to minimize eddy current losses, followed by core assembly check for mitered joints tightness and clamping pressure verification to prevent vibration noise. Coil winding progress test verifies conductor material purit,y tension control layer insulation application and turn accuracy using precision counters, dielectric withstand between layers. After winding insertion into core assembly test measures inter-winding clearances and secures compression bands for mechanical stability. Tank fabrication progress test examines corrugated wall welding seams for leak-proof integrity pressure resistance and surface treatment against corrosion. Final pre-assembly progress test confirms all components alignment bushings radiators valves installation and preliminary oil filling simulation to detect any assembly defects early ensuring seamless transition to full testing phase.
Design Tests
All transformers will be tested after finishing the production, test items as follows:
♦ Insulation Power Factor
♦ Ratio, Polarity, and Phase Relation
♦ Winding Resistance
♦ Impulse Tests
♦ On load Loss Test
♦ No Load Loss Test
♦ Leak Test
♦ DC Insulation Resistance Test
♦ Transformer Turns Ratio/TTR (All Tap Voltages)
♦ Impedance Voltage & Load Loss (Rated Voltage)
♦ Polarity, 1-Ph / Phase Relation, 3-Ph (Rated Voltage)
♦ Excitation & No-Load Loss (Rated Voltage)
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)
Transformer Factory Acceptance Test
Factory Acceptance Test (FAT) for 10kV oil immersed transformer begins with routine dielectric tests including applied voltage withstand and induced voltage test to verify insulation integrity between windings and ground per IEC 60076 standards. Winding resistance measurement uses the DC bridge method at the reference temperature to confirm conductor continuity and detect manufacturing anomalies. Voltage ratio and polarity/phase displacement check via turns ratio tester ensures accurate transformation ratios and vector group compliance (e.g. Dyn11). No-load loss and current test at rated voltage measures core performance exciting current harmonics, confirming low no-load losses and efficient magnetization. Load loss and impedance voltage test applies reduced voltage to the short-circuited secondary, calculating copper losses, short-circuit impedance for overload and stability assessment.
Routine Test - Leak Test
Purpose of Testing
The purpose of water leakage test is to check whether there is leakage in the equipment or system, to ensure that it has good sealing and safety during use. The integrity of the equipment can be verified by simulating the pressure or load conditions in the working environment.
Testing Equipment
Leakage current tester (e.g. Fluke, Hioki, Megger, etc.)
Voltage source (usually 500V, 1 KV or 2.5 KV, customized according to test requirements)
Temperature and humidity meter
Ground electrode
Voltage source (usually 500V, 1 KV or 2.5 KV, customized according to test requirements)
Temperature and humidity meter
Ground electrode
Pre-Test Preparation
Ensure that the test environment conditions are suitable for leak testing. Test between 20°C and 30°C. Relative humidity should be less than 75% to avoid moisture affecting the test equipment and results.
Test Progress
Connect the Test Instrument:
Properly connect the test equipment (such as a leak detector) to the pipe, container or sealing structure of the device under test.
Apply Test Voltage:
Apply the appropriate test pressure (e.g. 10 bar, 15 bar, etc.) depending on the equipment's operating pressure or test standard.
Properly connect the test equipment (such as a leak detector) to the pipe, container or sealing structure of the device under test.
Apply Test Voltage:
Apply the appropriate test pressure (e.g. 10 bar, 15 bar, etc.) depending on the equipment's operating pressure or test standard.
Measure and Record
Start the test and record the following parameters:
Applied test pressure
Leakage (can be monitored by flow meter or other equipment)
Time record (to ensure that the test time meets the standard requirements)
Initial pressure and final pressure (if any changes)
Applied test pressure
Leakage (can be monitored by flow meter or other equipment)
Time record (to ensure that the test time meets the standard requirements)
Initial pressure and final pressure (if any changes)
Check for leaks
Check for leaks on equipment surfaces and joints by using a foam detector, gas leak detector, or other suitable method.
Repeat Testing (if necessary)
If the test finds leakage or there is any doubt, repeat the test as necessary to verify the sealing of different locations or different equipment parts.
Evaluation Criteria (Reference)
No leakage (excellent): No leakage during the test, the equipment is completely sealed.
Minor leakage (good): Very small leakage is allowed, and it is necessary to judge whether it is qualified according to industry standards.
Minor leakage (good): Very small leakage is allowed, and it is necessary to judge whether it is qualified according to industry standards.
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
It is suitable for various scenarios such as power distribution in urban residential communities, power supply in industrial parks and factories, rural power grid transformation, grid connection of photovoltaic power stations, voltage boosting of wind farms, power supply in mining areas, substations in commercial complexes, and load centers of chemical and metallurgical enterprises, providing stable and efficient 10kV medium-voltage power distribution solutions.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
Transformers Packaging (1)
Transformers Packaging (2)
Transformers Packaging (3)
Transformers Packaging (4)
Transformers Packaging (5)
Transformers Packaging (6)
Transformers Packaging (7)
Transformers Packaging (8)
Related Products
5kVA Completely self-protected(CSP) Single Phase Pole Mounted Transformer
NPC ELECTRIC the production of the 5kVA Completely self-protected(CSP) Single Phase pole Mounted transformer is designed for reliable and efficient distribution of electrical power in residential and light commercial applications. Built to withstand harsh outdoor conditions, this transformer is equipped with a self-protection system that eliminates the need for external protection devices, offering enhanced safety and durability. The CSP feature ensures that the transformer can handle internal faults such as short circuits or overloads without causing damage to the system. This compact, oil-immersed transformer is easy to install on poles, making it ideal for overhead distribution in areas with limited space. It is designed to meet international standards, including ANSI, IEEE, and CSA, ensuring high-quality performance and long-lasting operation. The 5kVA CSP transformer is energy-efficient, providing stable voltage regulation and minimizing maintenance requirements, making it an excellent choice for both utility and commercial applications.
7MVA 22kV to 6.6kV Power Transformer ONAN Cooling Low Loss
The 6kV Three-Phase Oil-Immersed Power Transformer is designed for stable and efficient voltage conversion in industrial and commercial power distribution systems. With a durable oil-immersed insulation structure and high-quality copper windings, it offers excellent thermal performance, strong dielectric strength, and reliable operation under varying load conditions. Its compact design, robust core materials, and advanced cooling system ensure low losses, reduced noise, and long service life. This 6kV transformer is suitable for factories, mining sites, distribution stations, and utility networks requiring consistent and safe electrical power supply. Engineered to meet international standards, it provides dependable performance and high efficiency across diverse low-to-medium voltage applications.
25kVA Conventional Type Single Phase Pole Mounted Transformer
NPC ELECTRIC'S 25kVA Conventional Type Single Phase pole Mounted transformer are designed for servicing residential overhead distribution loads. They are also suitable for light commercial loads, industrial lighting and diversified power applications. These transformers are designed for the application conditions normally encountered on electric utility power distribution systems. Types CSP, CP, SP and S are all available. ISO 9001: 2008 Certified.
1000kVA Dry Type Transformer
NPC ELECTRIC 1000kVA Dry-Type Transformer offers efficient, oil-free power distribution with a compact design. Equipped with advanced insulation and cooling systems, it ensures safe and reliable operation with minimal maintenance. Ideal for industrial and commercial applications, it provides environmentally friendly and cost-effective performance.
33kV 600A Neutral Zig-zag Grounding Reactor Transformer
The 33kV 600A Neutral Zig-zag Grounding Reactor Transformer is a high-performance grounding solution designed to meet the strict requirements of IEC 60076-1, IEC 60076-5, IEC 60076-20, and GB/T 1094.6 standards, with oil quality tested according to ASTM D6871. This grounding transformer is engineered to provide effective neutral grounding, enhanced system stability, and fault current limitation in medium- and high-voltage networks. With a primary voltage of 33kV and 11432.0kVA rating, the transformer supports 100A power rating for 10 seconds, making it ideal for system grounding applications in substations, industrial facilities, and renewable energy projects. The ONAN cooling method provides efficient heat dissipation for continuous operation, while the use of high-grade mineral insulating oil ensures long-term performance and compliance with international safety standards.
2000kVA 35kV Wind Turbine Step-Up Transformer for Onshore Wind Farms
The Wind Turbine Step-Up Transformer 2000kVA 35kV is purpose-built for onshore wind farms, enabling efficient voltage conversion from wind turbine generators to medium-voltage collection networks. Designed to operate reliably under fluctuating wind loads and harsh outdoor conditions, this transformer ensures stable power transmission and reduced energy losses across wind power systems. The oil-immersed insulation structure provides excellent thermal stability and long service life, while the optimized magnetic core minimizes no-load losses and acoustic noise. High-quality windings and reinforced insulation withstand frequent load variations caused by changing wind speeds.FAQ From Customers
-
What is a Transformer?A transformer is an electrical device used to change the voltage of alternating current (AC). It works on the principle of electromagnetic induction, converting high-voltage current into low-voltage current or low-voltage current into high-voltage current. Transformers are widely used in power transmission, distribution systems, and various electronic devices.
-
What are the main uses of a transformer?The main use of a transformer is voltage conversion. Transformers are used in power transmission systems to help transfer electricity from power plants to consumers. In addition, transformers are also used in electronic devices such as chargers, televisions, power adapters, etc., to adjust the voltage to meet the requirements of different devices.
-
Do you have UL listed?Yes, our transformer has UL listed. We have exported to America many pad mounted transformer,substation transformer and HV.
Welcome your inquiry
Honesty, Integrity, Frugality, Activeness and Passion