3150kVA Oil Immersed Transformer
3150kVA Oil Immersed Transformer is a high-capacity three-phase power transformer optimized for efficient voltage transformation in 50/60Hz AC medium-voltage networks, with primary ratings commonly at 11kV, 22kV, 33kV, or 35kV (adaptable to 10–38.5kV) and secondary at 0.4kV, 0.69kV, 6.3kV, 10kV, or 11kV. Employing advanced high-permeability grain-oriented silicon steel core (S13/S20 series compliant) for dramatically reduced no-load losses (typically 3200–5400W), high-purity copper windings, and premium insulating oil (IEC 60296 compliant, dielectric >60kV/2.5mm), it achieves low load losses (around 18–22kW at 75°C), strong overload capability (up to 150–180% short-duration), noise below 65dB, and efficiency exceeding 99%.This transformer minimizes operational expenses, transmission losses, and environmental impact in large-scale industrial, utility, and renewable setups.
- 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 30/95kV
- Standards IEEE, ANSI, NEMA, IEC, CE
- Application data centers, and railway transportation hubs
- Power Rating 3150kVA
- 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
3150kVA Oil Immersed Transformer
Technical Specifications
Accessories
| Rated Power | 3150kVA | |
| 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 | 1850 kg | |
| Total Weight | 8300 kg | |
| Outline Dimensions（L×W×H）in. | 2650 × 2720 × 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
3150kVA Oil Immersed Transformer
The 3150kVA oil immersed transformer supports extensive customization for precise alignment with grid requirements, load profiles, environmental conditions, and regulatory demands. Primary voltages range from 11kV to 35kV (including 22kV, 33kV, 34.5kV variants), with secondary voltages configurable to 0.4kV, 0.69kV, 6.3kV, 10kV, 11kV, or specialized multi-winding setups. Voltage regulation options include multi-step off-circuit tap changers (±5% to ±10%) for stable fixed operation or on-load tap changers (OLTC, 17–33 positions with motorized drive) for real-time adjustment in dynamic renewable or industrial applications. Core materials offer high-grade grain-oriented silicon steel for standard efficiency or amorphous alloy to reduce no-load losses by up to 70%, delivering maximum energy savings. Winding choices feature premium copper for superior conductivity, heat resistance, and reliability or aluminum for cost-optimized high-power configurations.
Further tailoring includes cooling enhancements (ONAN primary with ONAF fans/pumps for extreme temperatures -40°C to +55°C or extended overloads), insulating oils (mineral, natural/synthetic esters per IEC 61099 for fire safety and eco-friendliness), and tank constructions with conservator/breather systems, hermetic alternatives, C5 marine-grade anti-corrosion protection, seismic bracing, or higher IP ratings for harsh/polluted sites.Accessories encompass online dissolved gas analysis (DGA), fiber-optic temperature sensors, SCADA-compatible RTUs, surge arresters, gas relays, and predictive monitoring modules. Impedance (6–10%), vector groups (Dyn11, YNd1, etc.), BIL classes (up to 200kV), frequency (50/60Hz), noise suppression packages, and compliance with IEC 60076, GB1094, ANSI/IEEE, or regional efficiency tiers are fully adaptable. Our specialists collaborate to engineer tailored solutions for primary substations, wind/solar aggregation, heavy mining, petrochemical facilities, or large commercial complexes, prioritizing peak efficiency, enhanced fault tolerance, minimized total ownership costs, and optimal integration.
Packing and Shipping
3150kVA Oil Immersed Transformer
Safeguarding the 3150kVA oil immersed transformer for international transport involves stringent protocols to protect core/winding precision, insulation integrity, and oil system from mechanical, thermal, and environmental stresses. Pre-packing inspections include tank hydrostatic/leak tests (1.5x rated), bushing/terminal torque confirmation, oil dielectric/acidity sampling (>60kV/2.5mm, <20ppm water), and relay/temperature device checks. Units typically ship conservator oil-filled under nitrogen positive pressure (0.02–0.06MPa) to avert oxidation/moisture; for oversized or restricted-weight shipments, oil is partially drained into sealed ISO-compliant tanks/drums, with vacuum degassing kits and matching high-purity oil provided for field restoration per IEC guidelines.
Detached parts receive dedicated protection: radiators foam-cushioned and crated with bracing, high-voltage bushings in vibration-proof reinforced boxes, OLTC assemblies secured and sealed, control panels wrapped with desiccants. The main body affixes to heavy-duty steel skids or ISPM-15 certified reinforced wooden/steel cradles with custom internal blocking, lateral supports, and shock-absorbing materials designed for 5–6g impacts in multimodal logistics. Packaging layers feature robust weatherproof tarpaulins, volatile corrosion inhibitors, humidity/temperature indicators, and electronic shock/tilt recorders for complete traceability.
Ocean freight, dominant for export, uses flat-rack, open-top, or break-bulk vessels with IMO lashing standards, salt-fog barriers, and protective shrouding; road/rail segments employ heavy-haul trailers with hydraulic suspension, balanced load cradles, and crane-accessible lift points. Export documentation includes invoices, packing lists, origin/conformity certificates, routine/type test reports, dimensional/lifting drawings, oil SDS, handling/installation manuals, and HS codes (8504.22/8504.23 for power transformers in this range).
We provide comprehensive logistics management from factory to site, including FOB/CIF/door terms, customs facilitation, insurance coverage, and premium services like third-party inspections, professional unloading supervision, oil filtration/degassing on arrival, erection oversight, and commissioning support. This thorough methodology eliminates transit damage risks, preserves as-manufactured condition, meets global compliance, and ensures efficient, secure delivery for utility, industrial, and renewable clients worldwide.
Detached parts receive dedicated protection: radiators foam-cushioned and crated with bracing, high-voltage bushings in vibration-proof reinforced boxes, OLTC assemblies secured and sealed, control panels wrapped with desiccants. The main body affixes to heavy-duty steel skids or ISPM-15 certified reinforced wooden/steel cradles with custom internal blocking, lateral supports, and shock-absorbing materials designed for 5–6g impacts in multimodal logistics. Packaging layers feature robust weatherproof tarpaulins, volatile corrosion inhibitors, humidity/temperature indicators, and electronic shock/tilt recorders for complete traceability.
Ocean freight, dominant for export, uses flat-rack, open-top, or break-bulk vessels with IMO lashing standards, salt-fog barriers, and protective shrouding; road/rail segments employ heavy-haul trailers with hydraulic suspension, balanced load cradles, and crane-accessible lift points. Export documentation includes invoices, packing lists, origin/conformity certificates, routine/type test reports, dimensional/lifting drawings, oil SDS, handling/installation manuals, and HS codes (8504.22/8504.23 for power transformers in this range).
We provide comprehensive logistics management from factory to site, including FOB/CIF/door terms, customs facilitation, insurance coverage, and premium services like third-party inspections, professional unloading supervision, oil filtration/degassing on arrival, erection oversight, and commissioning support. This thorough methodology eliminates transit damage risks, preserves as-manufactured condition, meets global compliance, and ensures efficient, secure delivery for utility, industrial, and renewable clients worldwide.
32
32 years of industry experience
Manufacturer Test
3150kVA Oil Immersed Transformer
Progress Test
Insulating oil progress testing for the 3150kVA oil immersed transformer evaluates breakdown voltage moisture acidity gas content and purity per IEC 60296 with filtration dehydration to ultra-low levels. Core-coil drying progress tracks vacuum oven cycles thermal profiles and dew point below -50°C for superior insulation. Tank filling progress oversees vacuum impregnation circulation degassing nitrogen blanketing and extended pressure hold leak tests. Protective device progress verifies Buchholz relay thresholds sudden pressure actuation temperature gauge calibration relief valve response and OLTC sequencing. Pre-shipment progress for the 3150kVA oil immersed transformer includes dimensional weight visual conformity labeling packaging verification shock trials and detailed photo digital records confirming full compliance and readiness for shipment.
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)
♦ Lightning Impulse
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)
Transformer Factory Acceptance Test
Factory Acceptance Test (FAT) for the 3150kVA oil immersed transformer begins with visual dimensional nameplate accessory coating review then insulation resistance PI tan-delta measurements. Separate-source withstand voltage and induced overvoltage tests validate insulation with PD <5pC. Winding DC resistance at 75°C confirms continuity joints and thermal factors. Voltage ratio phase vector group (Dyn11 etc.) polarity across taps with precision. No-load loss exciting current harmonics at rated voltage verify core efficiency low no-load and current compliance.
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 combined scenarios such as heavy-duty power supply in large industrial applications, voltage reduction in regional main substations, voltage boosting in wind and solar power plants, power systems in ports and mines, load centers in metallurgical and chemical enterprises, high-capacity power supply for data centers, and railway transportation hubs, providing 3150kVA of efficient medium-high voltage conversion and low-loss reliable operation.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
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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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