800kVA Oil Immersed Transformer
- 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 30/95kV
- Standards IEEE, ANSI, NEMA, IEC, GB
- Application Power Transmission and Distribution, Industrial Manufacturing, Commercial Facilities and New Energy Fields
- Power Rating 800kVA
- Certificate UL, CESI, CE
- Cooling Method ONAN, ONAN/ONAF, KNAN, KNAN/KNAF
- Oil Mineral Oil or FR3
- Opeartion Step Down & Step Up
Technical Specifications
Technical Specifications | ||
Rated Power | 800 kVA | |
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 | 675 kg | |
Total Weight | 3500 kg | |
Outline Dimensions(L×W×H)in. | 1620 × 880 × 1520(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
Packing and Shipping
The transformer body is reinforced with heavy wooden pallets and equipped with shock-proof rubber pads at the bottom to reduce the impact of vibration. The exterior is sealed with weather-resistant plastic film and covered with a moisture-proof and rust-proof protective layer to prevent oil leakage and environmental factors. All oil valves, bushings, and radiators are strictly sealed to prevent leakage or damage during transportation. The exterior of the transformer is packed in reinforced wooden boxes or steel frame structures, and the outer boxes are marked with signs such as "Do not dump", "Handle with care" and "Lifting Guide". Matching accessories and vulnerable parts such as high and low voltage bushings, temperature controllers, silicone desiccant, etc. They are packed separately and packed in special wooden boxes or thickened cartons. Each transformer is accompanied by a complete packing list, certificate of conformity, instruction manual and test report to ensure that customers can accept it correctly.
Domestic transportation uses professional flatbed trucks to ensure that the transformer is fixed firmly and reinforced with straps to prevent sliding. International transportation is carried out by container or bulk carrier, and an anti-vibration support structure is provided when necessary to ensure the stability of the equipment during long-distance transportation. All packaging complies with international shipping, rail, and road transportation standards, and additional protection measures can be provided according to customer needs.


Manufacturer Test

Progress Test
NPC ELECTRIC's 800kVA oil-immersed transformers undergo rigorous manufacturing process testing during production to ensure product quality and stable performance. First, the transformer core material is sheared and stacked with high precision to reduce no-load losses. Subsequently, the coils made of high-quality copper wire are strictly insulated and vacuum dried to remove moisture. After the coils and cores are assembled, preliminary electrical tests are carried out, including insulation resistance and winding DC resistance measurements. The transformer oil is filtered and degassed before being filled into the oil tank to ensure good insulation performance and heat dissipation. After assembly, the transformer undergoes type tests such as power frequency withstand voltage, induction withstand voltage, and partial discharge to ensure that the electrical performance meets the standards. Finally, the finished product undergoes a load test and a temperature rise test to verify stability under actual operating conditions. After all tests are completed and passed, the transformer will be packaged and prepared for shipment to the customer's designated location.

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
NPC ELECTRIC's 800kVA oil-immersed transformers undergo rigorous factory acceptance tests before leaving the factory to ensure that their performance meets international standards.
First, the transformer is visually inspected to confirm that the housing, terminal blocks, and nameplate information are intact. Then winding resistance test is performed to verify the integrity and conductivity of the coil. The insulation withstand voltage test ensures that the transformer can operate safely at rated voltage and has sufficient insulation strength. Short-circuit and no-load loss tests are used to measure the energy efficiency of the transformer to ensure that the power loss meets the design standards. The ratio test is used to confirm whether the voltage ratio of each winding meets the technical parameters.
After all tests are completed, a detailed test report is issued to ensure that the product meets customer and industry requirements.
Routine Test - Excitation & No-Load Loss (Rated Voltage)
Voltage source: usually rated voltage (such as 230V, 400V, 660V, customized according to equipment requirements)
Temperature and humidity meter: used to record ambient temperature and humidity conditions
Check the device terminals and wiring to ensure that the connection is secure and not loose or contaminated.
Ensure the test environment is suitable: relative humidity below 75%, no rain, and recommended temperature is 20-30°C.
Connect the test equipment to the appropriate terminals of the device under test and ensure that all connection points are properly grounded to avoid current leakage during the test.
Apply Test Voltage:
Select a suitable test voltage according to the rated voltage of the equipment (for example, the rated voltage is 11kV, 33kV or others), and ensure that the applied voltage is stable.
No-load loss
Excitation loss
Power factor
Voltage
Current
Ambient temperature and humidity during testing
No-load loss > rated loss (further inspection or corrective action required)

Application
Technical Advantages
Product Packaging
Related Products
FAQ From Customers
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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.