630kVA Dry Type 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 Dry type transformer
- BIL 30/95kV
- Standards IEEE, ANSI, NEMA,IEC,GB
- Application residential power distribution, power systems and distribution networks, office buildings, transportation facilities,theaters, hospitals, hotels etc
- Power Rating 630kVA
- Certificate UL ,CESI, ISO
- Cooling Method OA/OF
- Opeartion Step Down & Step Up
Technical Specifications
Technical Specifications | ||
Rated Power | 630 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 | |
Enclosure material | 304 Stainless Steel | |
Total Weight | 2580 kg | |
Outline Dimensions(L×W×H)in. | 1680×1460×1960(mm) |
HV Bushing |
LV Bushing |
Tap changer connector |
Lifting hook for complete transformer |
Name plate |
Customization Optional
Packing and Shipping
The 630kVA Dry-Type Transformer is carefully packed and shipped to ensure safe and secure delivery. The transformer is first wrapped in protective plastic or moisture-resistant film to shield it from dust, moisture, and environmental factors during transit. It is then placed on a sturdy wooden pallet or inside a custom-made wooden crate, providing solid support and protection from physical impacts during handling and transport.
To prevent movement, shock-absorbing materials, such as foam or bubble wrap, are used to cushion the transformer, ensuring it remains stable and undamaged.
The unit is clearly labeled with shipping marks, including weight, dimensions, and handling instructions, to ensure proper care during loading, unloading, and transportation.
The transformer is shipped through reliable and experienced logistics providers, adhering to international standards for packaging and shipping.
Once the transformer reaches its destination, the packaging is carefully removed, and the unit is thoroughly inspected for any potential shipping damage before installation.


Manufacturer Test

Progress Test
NPC Electric manufactures high-quality three-phase dry-type transformers under strict quality control protocols. The 630kVA Dry-Type Transformer undergoes a series of rigorous progress tests to ensure optimal performance and reliability. These tests include verification of the voltage ratio, insulation resistance, and load capacity under typical operational conditions. The transformer is also tested for temperature rise to confirm effective heat dissipation and safe operation. In addition, partial discharge and no-load loss tests are conducted to ensure the highest quality standards are met. All tests are performed in line with international standards, and the transformer is thoroughly inspected to guarantee its long-term performance and safety before delivery.

Design Tests
All transformer will be test after finished the production, test items as below:
♦ Insulation Power Factor
♦ 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)
♦ Excitation & No-Load Loss (Rated Voltage)
♦ Applied Voltage
♦ Induced Voltage
♦ Lightning Impulse
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise

Transformer Factory Acceptance Test
NPC Electric conducts rigorous quality control testing on every transformer or representative samples, as well as on specific components and materials, to ensure compliance with design specifications throughout the production process.
The Factory Acceptance Test (FAT) for a 630kVA three-phase dry-type transformer is a critical step performed before shipment to verify that the unit meets all applicable standards and delivers optimal performance. The FAT includes the following key procedures:
Visual Inspection: Evaluates the transformer’s physical condition, including the enclosure, terminals, and labeling, to ensure conformance with design and safety requirements.
Electrical Testing: Involves measuring winding resistance, insulation resistance, and performing turns ratio tests to validate electrical integrity and functionality.
Dielectric Strength Test: Applies high voltage across the insulation system to ensure it can endure both normal and transient operating voltages without failure.
Load Testing: Simulates real-world operating conditions to assess the transformer’s voltage regulation, temperature rise, and overall efficiency under load.
Protection Device Testing: Verifies the proper operation of integrated protective components such as thermal sensors, temperature relays, and tap changers (if applicable).
Routine Test - DC Insulation Resistance Test
Voltage source (usually 500V, 1000V, 2500V, or customized according to customer requirements)
Temperature and humidity meter (used to record the ambient temperature and humidity during the test to ensure that the test conditions meet the standard requirements.)
Perform the test under suitable environmental conditions. It is recommended to have a relative humidity below 75%, no rain, and a temperature range of 20-30°C to avoid moisture or temperature fluctuations affecting the test results.
Connect an insulation resistance tester to the high voltage terminal of the device under test and to ground.
Apply Test Voltage:
Select an appropriate test voltage based on the rated voltage of the equipment .
Insulation resistance value (MΩ)
Applied voltage
Ambient temperature and humidity during testing
500 MΩ ≤ Insulation resistance < 1000 MΩ (good)
100 MΩ ≤ Insulation resistance < 500 MΩ
Insulation resistance < 100 MΩ

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.