150kVA Oil Immersed Transformer
NPC ELECTRIC's 150kVA Oil Immersed Transformer is a compact and efficient power distribution solution designed for low to medium load applications. Utilizing a traditional oil-immersed insulation system, the transformer delivers stable dielectric performance and effective heat dissipation, ensuring reliable operation under continuous service conditions. The optimized core and winding structure reduces energy loss while maintaining consistent voltage output, making it suitable for decentralized power networks. With low operating noise and dependable overload capability, the transformer supports stable power supply for residential, commercial, and light industrial users. Its compact footprint and proven oil-filled technology make it an economical and practical choice for localized power distribution systems.
- 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 residential communities, rural power distribution networks
- Power Rating 150kVA
- 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
150kVA Oil Immersed Transformer
Technical Specifications
Accessories
| Rated Power | 150kVA | |
| 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 | 460 kg | |
| Total Weight | 1200 kg | |
| Outline Dimensions（L×W×H）in. | 1300 × 800 × 1400（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
150kVA Oil Immersed Transformer
NPC Electric 150kVA Oil Immersed Transformer offers flexible electrical customization to suit various local grid standards and application requirements. Primary and secondary voltage ratings can be configured to match different distribution networks, ensuring compatibility with residential and commercial power systems. Off-circuit tap changers can be selected to allow voltage adjustment, improving output stability under varying load conditions. Insulation level and temperature rise parameters may also be adjusted to align with specific operating environments.
Structural customization options enhance the transformer’s adaptability to diverse installation scenarios. The tank design can be modified for pole-mounted or ground-mounted applications, with optional surface treatments available for humid, dusty, or corrosive environments. Accessories such as oil level indicators, thermometer pockets, and protection devices can be integrated as required. These customization options enable the 150kVA oil immersed transformer to deliver reliable performance while meeting installation, safety, and environmental expectations.
Packing and Shipping
150kVA Oil Immersed Transformer
Each 150kVA Oil Immersed Transformer is prepared for shipment following a detailed inspection process to ensure quality and safety. Prior to packing, the transformer is cleaned, dried, and sealed to prevent moisture ingress and contamination. Electrical terminals and accessories are checked for secure installation, while removable components are properly protected to avoid damage during handling.
The transformer is placed on a stable wooden or steel base designed to support its weight and prevent movement during transportation. Protective wrapping materials are applied to shield the tank surface and bushings from vibration, dust, and minor impacts. The packing method complies with international logistics standards, making the 150kVA oil immersed transformer suitable for road transport, containerized sea freight, or multimodal shipping.
Shipping arrangements are coordinated according to customer delivery terms and project timelines. The manufacturer provides complete shipping documentation, including packing lists, inspection records, and compliance certificates, to support smooth customs clearance. Experienced logistics partners ensure efficient handling and timely delivery from factory to destination.
Upon arrival, clear unloading and handling instructions help ensure the transformer is received in good condition. Reliable packing and controlled shipping processes reduce transportation risks and help maintain the performance integrity of the 150kVA oil immersed transformer before installation and commissioning.
The transformer is placed on a stable wooden or steel base designed to support its weight and prevent movement during transportation. Protective wrapping materials are applied to shield the tank surface and bushings from vibration, dust, and minor impacts. The packing method complies with international logistics standards, making the 150kVA oil immersed transformer suitable for road transport, containerized sea freight, or multimodal shipping.
Shipping arrangements are coordinated according to customer delivery terms and project timelines. The manufacturer provides complete shipping documentation, including packing lists, inspection records, and compliance certificates, to support smooth customs clearance. Experienced logistics partners ensure efficient handling and timely delivery from factory to destination.
Upon arrival, clear unloading and handling instructions help ensure the transformer is received in good condition. Reliable packing and controlled shipping processes reduce transportation risks and help maintain the performance integrity of the 150kVA oil immersed transformer before installation and commissioning.
32
32 years of industry experience
Manufacturer Test
150kVA Oil Immersed Transformer
Progress Test
During manufacturing, the 150kVA Oil Immersed Transformer undergoes a series of progress tests to monitor quality and consistency at each stage. Core assembly inspections confirm proper lamination alignment to control magnetic losses, while winding process checks verify conductor placement and insulation accuracy. Intermediate electrical measurements, including insulation resistance and turns ratio testing, are performed to ensure the 150kVA oil immersed transformer meets design specifications prior to final assembly. Drying procedures, oil filling supervision, and sealing inspections are conducted to maintain dielectric strength and prevent leakage. By integrating product-specific parameters into each inspection step, the factory ensures the 150kVA oil immersed transformer maintains consistent quality, operational safety, and long-term performance before proceeding to final acceptance testing.
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
The Factory Acceptance Test for the 150kVA Oil Immersed Transformer is carried out in accordance with applicable transformer standards. Test items include winding resistance measurement, voltage ratio verification, applied voltage withstand testing, and insulation performance evaluation. These procedures confirm that the 150kVA oil immersed transformer satisfies electrical safety requirements and operational accuracy before shipment. No-load and load loss measurements, temperature rise checks, and oil dielectric strength tests are performed to validate performance. Completion of the FAT process ensures the 150kVA oil immersed transformer is ready for reliable service in real-world distribution applications.
Routine Test - No Load Loss Test
Purpose of Testing
The purpose of No Load Loss Test is to measure the power loss of the equipment when it is not loaded to evaluate the iron loss and other core losses. This test can help understand the energy efficiency of the equipment and help determine the performance of the transformer or motor when it is running at no load.
Testing Equipment
No Load Loss tester (e.g. OMICRON, Megger, Schneider Electric, etc.)
Voltage source (usually 230V, 400V or customized according to customer requirements to adapt to different equipment)
Power analyzer (used to measure power loss and efficiency)
Ammeter and voltmeter
Temperature and humidity meter
Voltage source (usually 230V, 400V or customized according to customer requirements to adapt to different equipment)
Power analyzer (used to measure power loss and efficiency)
Ammeter and voltmeter
Temperature and humidity meter
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
Connect the Test Instrument:
Connect the test equipment to the high voltage side of the transformer, making sure the wiring is correct and the equipment is grounded.
Apply Test Voltage:
Usually it is 110% of the rated voltage, for example, if the rated voltage of the transformer is 33 KV, apply 36.3 KV (110%).
Connect the test equipment to the high voltage side of the transformer, making sure the wiring is correct and the equipment is grounded.
Apply Test Voltage:
Usually it is 110% of the rated voltage, for example, if the rated voltage of the transformer is 33 KV, apply 36.3 KV (110%).
Measure and Record
Start the test and record the following parameters:
No Load Current
No Load Loss
Power Factor
Current
Voltage
Temperature and Humidity
No Load Current
No Load Loss
Power Factor
Current
Voltage
Temperature and Humidity
Temperature Correction
The power loss of the test results is corrected to a reference temperature (usually 20°C) to ensure an accurate evaluation.
Repeat Testing (if necessary)
Test at different rated voltages, especially when the transformer has multiple capacity levels, and perform no-load loss tests for each capacity level separately.
Evaluation Criteria (Reference)
No-load loss ≤ 0.2% rated power (excellent)
No-load loss < 0.2% ≤ 0.5% rated power (good)
No-load loss > 0.5% rated power (further inspection or corrective action required)
No-load loss < 0.2% ≤ 0.5% rated power (good)
No-load loss > 0.5% rated power (further inspection or corrective action required)
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
150kVA Oil Immersed Transformer is suitable for residential communities, rural power distribution networks, commercial buildings, and school power supply systems, providing stable and safe power conversion for low-load scenarios.
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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