x
300kVA Oil Immersed Transformer1
300kVA Oil Immersed Transformer2
300kVA Oil Immersed Transformer4
300kVA Oil Immersed Transformer1
300kVA Oil Immersed Transformer2
300kVA Oil Immersed Transformer4

300kVA Oil Immersed Transformer

In the field of power transmission and distribution, NPC ELECTRIC 300kVA oil-immersed transformer stands out with its excellent performance, providing reliable power support for various power consumption scenarios. The transformer is carefully wound with high-quality silicon steel sheets and electromagnetic wires, with extremely low no-load loss and load loss, which greatly improves the efficiency of power conversion and effectively reduces electricity costs. It is widely used in industrial plants, commercial centers, residential communities, infrastructure construction, and other fields to meet the power needs of different scenarios.
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
Application Residential Areas And Small Communities, Energy And Power Distribution Stations, Wind And Solar Power Generation Systems Etc
Power Rating 300kVA
Certificate ISO, CE, UL
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

300kVA Oil Immersed Transformer
Technical Specifications
Accessories
  Technical Specifications
Rated Power 300 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 430 kg
Total Weight 1650 kg
Outline Dimensions(L×W×H)in. 1700 × 1250 × 1800(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

300kVA Oil Immersed Transformer
NPC ELECTRIC’s three-phase oil-immersed transformers can be fully customized to meet your specific requirements. The Optional Specifications for a 300kVA Three-Phase Oil-Immersed Transformer offer several customizable features to meet specific operational, environmental, and regulatory requirements. These options can include different types of tap changers, such as manual or on-load tap changers, for adjusting voltage levels while the transformer is in operation. Enhanced protection systems like Buchholz relays, gas-actuated relays, and temperature sensors may be added to monitor internal conditions and ensure safety during fault conditions. The transformer can also be equipped with specialized bushings, such as composite or porcelain, to suit varying voltage levels and environmental conditions.
For installations in challenging environments, options for corrosion-resistant coatings, weatherproof enclosures, or special oil types, such as biodegradable or high-performance insulating oils, may be included to extend the transformer's lifespan. Additionally, noise reduction options like acoustic enclosures or vibration dampers may be offered for quieter operation. Customization of the transformer’s insulation class, cooling methods (such as ONAN or ONAF), and compliance with specific industry standards or certifications (e.g., IEC, IEEE) are also available, ensuring the transformer meets local regulations and performance expectations.

Packing and Shipping

300kVA Oil Immersed Transformer
NPC ELECTRIC single-phase pad-mounted transformers are designed to be securely packaged for sea freight transport, ensuring safe delivery across long distances.
For this purpose, the Packing and Shipping of a 300kVA Three-Phase Oil-Immersed Transformer involves a series of steps to ensure the safe and secure transport of the transformer from the manufacturer to the installation site. The process begins with a thorough inspection and cleaning of the transformer to remove any dirt, debris, or foreign materials. The transformer is then carefully prepared for packaging, with all loose or delicate components, such as bushings, tap changers, and protective devices, securely fastened or removed to avoid any damage during transit.
The transformer is placed onto a sturdy, custom-designed wooden or metal skid, ensuring proper weight distribution and preventing movement during shipping. For added protection, the transformer is wrapped in weather-resistant and moisture-proof materials, such as shrink wrap or tarpaulins, to safeguard against external environmental factors like dust, rain, or temperature variations. Additionally, if the transformer contains oil, the packaging is designed to ensure that the oil remains at the proper level and that there are no leaks or contamination risks during transit.
The transformer is then loaded into a wooden or metal crate that provides additional cushioning and structural integrity to prevent mechanical damage. The shipping crate is appropriately labeled with necessary details, including handling instructions, weight, dimensions, and safety warnings such as "Fragile" or "Keep Upright." The packaging also includes clear instructions on how to safely lift and move the transformer using cranes or forklifts. Once packed, the transformer is ready to be transported via the most suitable mode of transport—truck, rail, or sea container—depending on the distance and delivery method. Upon arrival at the destination, the transformer is carefully unloaded, inspected again for any damage, and prepared for installation. This meticulous packing and shipping process ensures that the transformer reaches its final location in optimal condition and is ready for operation.
300kVA Oil Immersed Transformer package
300kVA Oil Immersed Transformer package mini
32
32 years of industry experience

Manufacturer Test

300kVA Oil Immersed Transformer
300kVA Oil Immersed Transformer Progress Test

Progress Test

NPC Electric manufactures three-phase oil-immersed transformers the strict quality control. The Optional Specifications for a 300kVA Three-Phase Oil-Immersed Transformer offer several customizable features to meet specific operational, environmental, and regulatory requirements. These options can include different types of tap changers, such as manual or on-load tap changers, for adjusting voltage levels while the transformer is in operation. Enhanced protection systems like Buchholz relays, gas-actuated relays, and temperature sensors may be added to monitor internal conditions and ensure safety during fault conditions. The transformer can also be equipped with specialized bushings, such as composite or porcelain, to suit varying voltage levels and environmental conditions. For installations in challenging environments, options for corrosion-resistant coatings, weatherproof enclosures, or special oil types, such as biodegradable or high-performance insulating oils, may be included to extend the transformer's lifespan. Additionally, noise reduction options like acoustic enclosures or vibration dampers may be offered for quieter operation. Customization of the transformer’s insulation class, cooling methods (such as ONAN or ONAF), and compliance with specific industry standards or certifications (e.g., IEC, IEEE) are also available, ensuring the transformer meets local regulations and performance expectations.

300kVA Oil Immersed Transformer  Design Tests

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)

China NPC ELECTRIC

Transformer Factory Acceptance Test

The Transformer Factory Acceptance Test (FAT) for a 300kVA three-phase Oil immersed transformer is an essential procedure conducted before shipment to ensure the transformer meets all required standards and performs optimally. During the FAT, several critical tests are carried out:

Appearance and structure inspection

Shell structural strength: In addition to checking the appearance for damage and deformation, the transformer shell should be properly knocked to check whether the structural strength of the shell meets the requirements and whether there is any internal looseness or abnormal sound. At the same time, check whether the grounding of the shell is good, and the grounding resistance should not be greater than the specified value.

Accessory installation accuracy: Check whether the installation angle and spacing of the radiator meet the design requirements to ensure good heat dissipation. The connecting pipe of the oil pillow should not be twisted or blocked, the valve operation should be flexible, and the seal should be reliable. The installation position of the gas relay should be accurate, and the sealing gasket of its connecting flange should be installed correctly without extrusion deformation.

Noise and vibration test

When the transformer is in no-load and load operation, use a noise tester to measure the noise level of the transformer at the specified measurement position. The noise value should meet the requirements of national standards and generally should not exceed the specified limit. At the same time, use a vibration tester to detect the vibration of the transformer, analyze the vibration frequency and amplitude, and determine whether the transformer is running smoothly and whether there are any abnormal vibration sources.

Routine Test - On load Loss Test

Purpose of Testing
The purpose of On-load Loss Test is to measure the active power loss of the transformer under rated voltage and rated load, evaluate its energy efficiency level and design compliance, and provide a basis for energy consumption calculation and performance optimization during operation.
Testing Equipment
Power transformer test system (e.g. OMICRON, ISA, Tettex, Vanguard, etc.)
Voltage source and current source (usually rated voltage, or adjusted according to the test standard, such as 10 KV, 20 KV, 35 KV, etc.)
Temperature and humidity meter (used to record ambient temperature and humidity for correction of test data)
Pre-Test Preparation
Disconnect the transformer high voltage, low voltage and neutral power supply to ensure that the equipment is properly grounded and safely discharged.
The test environment should be dry and rainless, with a relative humidity of less than 75% and a recommended temperature range of 20–30°C.
Test Progress
Connect the Test Instrument:
Connect the test equipment to the appropriate terminals of the device under test and ensure that all wiring is correct and the device is well grounded.
Apply Test Voltage:
Apply the specified test voltage at the rated frequency and adjust the low voltage side to maintain the rated current (or specified current).
Measure and Record
Start the test and record the following parameters:
On-Load Loss Power
Input Power and Output Power
Current
Voltage
Temperature (temperature rise or winding temperature)
Ambient temperature and humidity during the test
Temperature Correction
The measured loss data is corrected based on a reference temperature (usually 20°C) to ensure the accuracy of the results.
Repeat Testing (if necessary)
Test different tap positions (Tap Changer) and record and compare the load loss data of each tap point.
Evaluation Criteria (Reference)
Evaluate the test results based on the equipment type and manufacturer requirements. If the load losses are low and the efficiency is high, it is considered "normal". If the load losses are too high or the efficiency is low, further inspection or corrective action is required.
*These comprehensive tests ensure that each transformer meets performance standards and operates reliably under various conditions.
30kVA Oil Immersed Transformer Routine Test

Technical Advantages

● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions

Product Packaging

Transformers Packaging (1)
Transformers Packaging (1)
Transformers Packaging (2)
Transformers Packaging (2)
Transformers Packaging (3)
Transformers Packaging (3)
Transformers Packaging (4)
Transformers Packaging (4)
Transformers Packaging (5)
Transformers Packaging (5)
Transformers Packaging (6)
Transformers Packaging (6)
Transformers Packaging (7)
Transformers Packaging (7)
Transformers Packaging (8)
Transformers Packaging (8)

Related Products

FAQ From Customers

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.
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.
Do you have UL listed?
Yes, our transformer has UL listed. We have exported to America many pad mounted transformer,substation transformer and HV.

Welcome your inquiry

Honesty, Integrity, Frugality, Activeness and Passion