450kVA Oil Immersed Transformer
The 450kVA Oil Immersed Transformer is a reliable three-phase distribution transformer engineered for medium-voltage step-down applications in 50/60Hz AC systems, typically with primary voltages of 11kV or 33kV (options for 6kV/10kV/20kV) and secondary at 0.4kV/0.415kV/0.433kV. High-grade cold-rolled grain-oriented silicon steel core with low-loss lamination reduces no-load losses, while copper or aluminum windings paired with premium mineral oil minimize load losses and enable ONAN cooling for strong overload capacity. Compliant with IEC 60076, GB/T6451, and energy efficiency standards (e.g., S11/S13 series), it achieves high overall efficiency (>98-99%) at typical loads, low noise (<55dB), and reduced total ownership costs for residential, commercial, and light industrial power distribution.
- Primary Voltage Ratings 34.5-19.92/13.8-7.957/13.2-7.62/12.47-7.2, 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 11/33kV
- Standards IEEE, ANSI, NEMA, IEC, CE
- Application schools and hospitals, new energy grid, data centers
- Power Rating 450kVA
- 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
450kVA Oil Immersed Transformer
Technical Specifications
Accessories
| Rated Power | 450kVA | |
| 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 | 950 kg | |
| Total Weight | 5200 kg | |
| Outline Dimensions（L×W×H）in. | 2750 × 1850 × 2550（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
450kVA Oil Immersed Transformer
The 450kVA oil immersed transformer supports flexible customization to meet specific voltage, efficiency, and installation requirements across various grids and applications. Standard configurations include primary voltages of 11kV or 33kV (with alternatives like 6.6kV/10kV/20kV/22kV) and secondary voltages at 0.4kV, 0.415kV, 0.433kV, or custom low-voltage outputs for specialized loads. Off-circuit tap changers offer ±2×2.5% or ±5% adjustment for voltage stabilization, while on-load tap changers (OLTC) can be added for dynamic regulation in fluctuating networks. Core materials range from conventional grain-oriented silicon steel for standard performance to amorphous alloy for up to 60-70% no-load loss reduction, enhancing energy savings. Winding options provide high-conductivity copper for superior efficiency and longevity or aluminum for cost-effective designs without compromising reliability.
Further personalization covers cooling upgrades (ONAN to additional radiators for high-ambient temperatures up to +50°C or forced air variants), insulating oils (mineral, bio-based esters for fire safety and environmental compliance per IEC 61099), and tank enhancements such as full hermetic sealing, anti-corrosion coatings (C3/C5 grades), seismic reinforcements, or higher IP ratings for outdoor/polluted sites. Accessories include oil level gauges, winding temperature sensors, smart monitoring modules (IoT for remote diagnostics), gas relays, and conservator options if preferred over hermetic. Impedance (4-6%), vector groups (Dyn11, Yyn0, etc.), BIL insulation (75kV for 11kV, 170kV for 33kV), frequency (50/60Hz), noise reduction packages, and adherence to IEC 60076, GB1094, or regional efficiency classes (e.g., EU Ecodesign Tier 2) are fully configurable. Our team partners closely with clients to tailor solutions for utility feeders, commercial buildings, small factories, or renewable tie-ins, optimizing for lifecycle cost reduction through high efficiency, low maintenance, and perfect system compatibility.
Packing and Shipping
450kVA Oil Immersed Transformer
Transporting the 450kVA oil immersed transformer necessitates careful protective measures to maintain core/winding alignment, oil integrity, and overall factory condition during global logistics. Pre-packing inspections encompass tank leak/pressure tests (positive hold verification), bushing and terminal torque checks, oil dielectric sampling (>50kV/2.5mm standard), and accessory operation confirmation. Units typically ship oil-filled under a nitrogen blanket (0.02-0.05MPa) to prevent moisture ingress and oxidation; for weight-restricted routes, oil may be partially drained into sealed drums with accompanying vacuum filling apparatus and matching high-purity oil reserves for on-site restoration in line with IEC guidelines.
Detached components receive individual safeguarding: radiators are padded and crated with anti-vibration materials, bushings in shock-resistant boxes, and control accessories sealed against dust/humidity with desiccants. The main tank secures to robust wooden ISPM-15 compliant crates or steel skids featuring custom blocking, lateral braces, and shock-absorbing elements capable of withstanding typical transport forces (up to 4-5g). Packaging includes multi-layer weatherproof barriers, volatile corrosion inhibitors, humidity/temperature indicators, and shock/tilt loggers for handling accountability throughout transit.
Ocean freight, the most common for export, utilizes flat-rack or open-top containers with IMO-standard lashing, salt-resistant wraps, and protective sheeting; road/rail segments employ low-bed trailers with balanced load distribution and marked crane lift points. Comprehensive export paperwork bundles commercial invoices, packing lists, certificates of origin/conformity, routine test reports, dimensional/lifting diagrams, oil SDS, installation manuals, and HS code declarations (8504.21 for distribution transformers ≤650kVA).
We coordinate complete logistics chains from factory departure to final destination, providing FOB/CIF terms, customs support, insurance options, and value-added services such as third-party inspections, professional unloading supervision, oil processing/filtering on arrival, erection guidance, and commissioning assistance. This thorough process safeguards against damage, ensures regulatory compliance, preserves performance characteristics, and delivers reliable, on-time arrival for customers worldwide in distribution, commercial, and light industrial sectors.
Detached components receive individual safeguarding: radiators are padded and crated with anti-vibration materials, bushings in shock-resistant boxes, and control accessories sealed against dust/humidity with desiccants. The main tank secures to robust wooden ISPM-15 compliant crates or steel skids featuring custom blocking, lateral braces, and shock-absorbing elements capable of withstanding typical transport forces (up to 4-5g). Packaging includes multi-layer weatherproof barriers, volatile corrosion inhibitors, humidity/temperature indicators, and shock/tilt loggers for handling accountability throughout transit.
Ocean freight, the most common for export, utilizes flat-rack or open-top containers with IMO-standard lashing, salt-resistant wraps, and protective sheeting; road/rail segments employ low-bed trailers with balanced load distribution and marked crane lift points. Comprehensive export paperwork bundles commercial invoices, packing lists, certificates of origin/conformity, routine test reports, dimensional/lifting diagrams, oil SDS, installation manuals, and HS code declarations (8504.21 for distribution transformers ≤650kVA).
We coordinate complete logistics chains from factory departure to final destination, providing FOB/CIF terms, customs support, insurance options, and value-added services such as third-party inspections, professional unloading supervision, oil processing/filtering on arrival, erection guidance, and commissioning assistance. This thorough process safeguards against damage, ensures regulatory compliance, preserves performance characteristics, and delivers reliable, on-time arrival for customers worldwide in distribution, commercial, and light industrial sectors.
32
32 years of industry experience
Manufacturer Test
450kVA Oil Immersed Transformer
Progress Test
Progress testing for 450kVA oil immersed transformer starts with silicon steel sheet inspection for thickness uniformity insulation coating magnetic permeability and burr-free edges via Epstein frame to minimize core losses then core stacking verifies precise mitered joints clamping torque uniformity and vibration suppression features. Winding process progress monitors conductor material purity enamel insulation application automated tension control turn precision and inter-layer dielectric strength checks post-winding. Core-coil assembly progress confirms adequate radial/axial clearances barrier placement end insulation compression and short-circuit force resistant structures. Tank production progress evaluates weld seam continuity hydrostatic pressure testing surface blasting multi-layer paint thickness and corrosion protection adherence pre-assembly progress checks bushing radiator valve alignment accessory installation and preliminary vacuum/pressure integrity tests to identify early issues ensuring smooth transition to detailed qualification stages.
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 450kVA oil immersed transformer begins with routine visual dimensional nameplate accessory and coating checks then insulation resistance polarization index tan-delta measurements. Separate-source withstand voltage (e.g. 28-35kV/1min for 11kV class) and induced overvoltage tests confirm major insulation with PD <10pC. Winding DC resistance corrected to 75°C verifies continuity and joint integrity. Voltage ratio phase displacement vector group (Dyn11 etc.) and polarity tested across taps with high accuracy. No-load loss exciting current and harmonics measured at rated voltage ensuring low no-load performance and current compliance.
Routine Test - Transformer Turns Ratio/TTR (All Tap Voltages)
Purpose of Testing
The purpose of the transformer turns ratio (TTR) test is to confirm whether the voltage ratio between each tap of the transformer meets the design requirements and ensure that the transformer winding is connected correctly. By measuring the voltage ratio of each tap, it is possible to detect whether there is a fault or deviation in the transformer winding.
Testing Equipment
TTR tester: such as Doble, Megger, Omicron and other brands of transformer winding ratio tester.
Voltage source: usually AC 10 V to 30 V , used to test different voltages for each tap.
Temperature and humidity meter: used to record environmental conditions during the test to ensure test accuracy.
Current probe: used to measure the load current of the winding and ensure the accuracy of the test results.
Voltage source: usually AC 10 V to 30 V , used to test different voltages for each tap.
Temperature and humidity meter: used to record environmental conditions during the test to ensure test accuracy.
Current probe: used to measure the load current of the winding and ensure the accuracy of the test results.
Pre-Test Preparation
Disconnect all transformer tap-changers from the power supply and ensure that all equipment is properly grounded and discharged.
Perform the test under suitable environmental conditions: relative humidity below 75% and no rain (recommended temperature: 20-30°C). Avoid high humidity or bad weather that may affect the test accuracy.
Perform the test under suitable environmental conditions: relative humidity below 75% and no rain (recommended temperature: 20-30°C). Avoid high humidity or bad weather that may affect the test accuracy.
Test Progress
Perform the test under suitable environmental conditions: relative humidity below 75% and no rain (recommended temperature: 20-30°C). Avoid high humidity or bad weather that may affect the test accuracy.
Measure and Record
Start the test and record the following parameters:
The voltage ratio between the windings
Deviation of the measured value from the rated ratio
The voltage ratio between the windings
Deviation of the measured value from the rated ratio
Temperature Correction
If necessary, perform temperature correction on the measured turns ratio data (especially when testing at higher or lower temperatures). Generally, the standard reference temperature for temperature correction is 20°C.
Repeat Testing (if necessary)
Test the transformer's windings of different voltage levels (high voltage, medium voltage, and low voltage) separately to ensure that the turns ratios of all windings are normal.
Evaluation Criteria (Reference)
Turns ratio error ≤ 0.5% (pass)
0.5% < Turns ratio error ≤ 1% (caution)
Turns ratio error > 1% (further inspection or corrective action required)
0.5% < Turns ratio error ≤ 1% (caution)
Turns ratio error > 1% (further inspection or corrective action required)
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
It is widely used in 11kV/33kV power distribution networks for combined applications such as urban communities, light industrial parks, critical power supply for shopping malls and hotels, backup power supply for schools and hospitals, new energy grid connection points, and data centers, ensuring stable overload tolerance and low-loss 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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