6kV Three-Phase Oil-Immersed Power Transformer
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.
- Primary Voltage Ratings 35kV, 34.5kV, 33kV, 46kV or others
- Secondary Voltage Ratings 13.8kV 6kV 10kV or others
- H.V. Tap Range ±8×1.25% or others
- Type Oil-immersed power transformer
- BIL 6kV
- Standards IEEE, ANSI, NEMA, IEC, CE
- Application mining operations, oil & gas facilities
- Power Rating 1000kVA 1250kVA
- Certificate UL, CESI, IEEE
- Cooling Method ONAN/ONAF
- Oil Mineral Oil or FR3
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
6kV Three-Phase Oil-Immersed Power Transformer
Technical Specifications
Accessories
| Rated Power | 1000kVA 1250kVA | |
| Rating Primary Voltage | 6kV, 35kV | |
| Secondary Voltage |
6.6kV 10kV 13.8kV 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 | |
| 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
6kV Three-Phase Oil-Immersed Power Transformer
The 6kV Three-Phase Oil-Immersed Power Transformer provides a wide range of customization options to meet different power system requirements. Customers may choose specific voltage ratios, impedance values, and vector groups to ensure compatibility with their electrical networks. Optional cooling methods such as ONAN or ONAF can be selected based on load conditions and environmental factors. Core material upgrades, copper or aluminum winding choices, and low-loss designs are also available to enhance efficiency and reduce operational costs.
Additional customized features include protection accessories like Buchholz relays, temperature controllers, oil level indicators, and pressure relief devices. Smart monitoring options such as online temperature sensors, DGA analyzers, and IoT-based remote supervision can be integrated for real-time performance tracking. With structural options such as anti-corrosion coatings, enhanced tank strength, and noise-reduction designs, this 6kV oil-immersed transformer can be tailored for various industrial, mining, and utility distribution applications.
Packing and Shipping
6kV Three-Phase Oil-Immersed Power Transformer
The 6kV Three-Phase Oil-Immersed Power Transformer follows strict packing and shipping procedures to ensure safe transport and problem-free installation. Before packaging, the transformer undergoes cleaning, drying, and oil sealing to prevent moisture intrusion. All bushings, valves, and external fittings are protected with shock-absorbing covers, moisture-proof wrapping, and anti-corrosion coatings. Desiccants are placed in relevant areas to maintain dryness during transit.
The transformer is mounted onto a reinforced steel or wooden skid capable of supporting its weight and preventing movement. Multiple layers of protective materials—including waterproof films, foam padding, and high-strength straps—are applied to secure the unit and protect it from vibration, impact, and harsh weather conditions. Sensitive components like gauges, sensors, and OLTC accessories are packed separately or reinforced with special housings.
For domestic transport, heavy-duty trucks with vibration-reducing suspension systems are used. For overseas delivery, the transformer is loaded onto flat-rack or open-top containers using certified lifting points and cranes that prevent structural stress. All loading procedures follow IEC and maritime safety standards, and shock/tilt indicators may be installed for monitoring during transit.
Upon arrival, unloading is carried out under professional supervision. Packaging is removed only after the transformer passes a final inspection. These meticulous packing and shipping procedures ensure the 6kV oil-immersed transformer arrives safely and ready for immediate installation.
The transformer is mounted onto a reinforced steel or wooden skid capable of supporting its weight and preventing movement. Multiple layers of protective materials—including waterproof films, foam padding, and high-strength straps—are applied to secure the unit and protect it from vibration, impact, and harsh weather conditions. Sensitive components like gauges, sensors, and OLTC accessories are packed separately or reinforced with special housings.
For domestic transport, heavy-duty trucks with vibration-reducing suspension systems are used. For overseas delivery, the transformer is loaded onto flat-rack or open-top containers using certified lifting points and cranes that prevent structural stress. All loading procedures follow IEC and maritime safety standards, and shock/tilt indicators may be installed for monitoring during transit.
Upon arrival, unloading is carried out under professional supervision. Packaging is removed only after the transformer passes a final inspection. These meticulous packing and shipping procedures ensure the 6kV oil-immersed transformer arrives safely and ready for immediate installation.
32
32 years of industry experience
Manufacturer Test
6kV Three-Phase Oil-Immersed Power Transformer
Progress Test
During production of the 6kV Three-Phase Oil-Immersed Power Transformer, strict process tests are performed to ensure manufacturing accuracy. Core lamination checks, coil winding tension inspection, and insulation drying verification occur at each stage. Intermediate electrical tests—such as turn ratio measurement, insulation resistance testing, and partial discharge checks—are conducted to confirm electrical performance. Mechanical strength tests, pressure tightness checks, and vacuum oil-filling monitoring further ensure reliability. These ongoing progress tests guarantee consistent quality and compliance with industry standards.
Design Tests
All transformer will be test after finished the production, test items as below:
♦ 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)
♦ Applied Voltage
♦ Induced Voltage
♦ Lightning Impulse
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)
Transformer Factory Acceptance Test
The Factory Acceptance Test (FAT) for the 6kV Three-Phase Oil-Immersed Power Transformer verifies full compliance with IEC and customer specifications. FAT includes visual inspection, winding resistance measurement, turn ratio testing, and insulation resistance checks. High-voltage dielectric tests—such as induced voltage, AC withstand, and partial discharge tests—ensure strong insulation performance. Functional tests on cooling systems, protection devices, and monitoring accessories confirm operational reliability. These comprehensive FAT procedures ensure the transformer is safe, efficient, and ready for installation.
Routine Test - Induced Voltage
Purpose of Testing
The purpose of the Induced Voltage test is to simulate the electrical stress that the equipment may encounter under actual working conditions by applying an induced voltage, thereby evaluating the tolerance and stability of the equipment's insulation system. This test helps to detect the insulation performance of the equipment under high voltage conditions and ensure its safety and reliability in operation.
Testing Equipment
Induced Voltage Tester (e.g. OMICRON, Megger, HioKI, etc.)
AC voltage source, commonly 2 kV, 5 kV, 10 kV, or customized according to test requirements.
Environmental thermometer and hygrometer, used to record the temperature and humidity of the environment for appropriate test evaluation.
AC voltage source, commonly 2 kV, 5 kV, 10 kV, or customized according to test requirements.
Environmental thermometer and hygrometer, used to record the temperature and humidity of the environment for appropriate test evaluation.
Pre-Test Preparation
Disconnect all relevant power supplies and ensure that the equipment is properly grounded and discharged.
Check the connection wires and terminals to ensure they are secure and free of contamination.
Test under suitable environmental conditions: relative humidity below 75%, no rain (recommended temperature: 20-30°C).
Check the connection wires and terminals to ensure they are secure and free of contamination.
Test under suitable environmental conditions: relative humidity below 75%, no rain (recommended temperature: 20-30°C).
Test Progress
Connect the Test Instrument:
Connect the test equipment to the appropriate terminals or bushings of the device under test, ensuring that the connections are secure and properly grounded.
Apply Test Voltage:
Select the appropriate induction voltage according to the rated voltage and standard of the equipment.
Connect the test equipment to the appropriate terminals or bushings of the device under test, ensuring that the connections are secure and properly grounded.
Apply Test Voltage:
Select the appropriate induction voltage according to the rated voltage and standard of the equipment.
Measure and Record
Start the test and record the following parameters:
Induced Voltage
Applied Current
Voltage peak, stability and waveform (waveform analysis)
Any abnormal current or voltage changes during the measurement process.
Induced Voltage
Applied Current
Voltage peak, stability and waveform (waveform analysis)
Any abnormal current or voltage changes during the measurement process.
Temperature Correction
The measured induced voltage data is corrected to the reference temperature (usually 20°C) to ensure the accuracy of the test results.
Repeat Testing (if necessary)
If necessary, test different windings (HV, MV, LV) and bushings separately and compare the results at different test points.
Evaluation Criteria (Reference)
Inductive voltage ≤ 1% (Excellent): normally and meets safety standards.
1% < Inductive voltage ≤ 3% (Good): still within acceptable range.
Inductive voltage > 3% : faulty or not meet safety requirements and requires further analysis and repair.
1% < Inductive voltage ≤ 3% (Good): still within acceptable range.
Inductive voltage > 3% : faulty or not meet safety requirements and requires further analysis and repair.
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
It serves as the core step-down equipment in private 35kV/6.3kV or 10kV/6.3kV substations for large manufacturing plants (cement, metallurgy, automotive, textiles), mining operations, oil & gas facilities, and port terminals, reliably supplying heavy machinery, conveyor systems, compressors, and welding equipment with stable 6kV power.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
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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.
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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.
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Do you have UL listed?Yes, our transformer has UL listed. We have exported to America many pad mounted transformer,substation transformer and HV.
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