630kVA Dry Type Transformer
NPC ELECTRIC 630kVA Dry-Type Transformer is a compact, oil-free solution for reliable power distribution. With advanced insulation and cooling systems, it ensures safe, low-maintenance operation, making it ideal for industrial and commercial applications. Offering 630kVA capacity, it delivers efficient, environmentally friendly, and cost-effective performance. Compliant with DOE amended energy conservation standards (finalized 2024, mandatory from April 23, 2029, with 20% loss reduction for three-phase low-voltage dry-type units), ANSI/IEEE C57.12.01, NEMA ST-20, UL 1561, and CSA standards, this low-voltage (≤600V) transformer minimizes no-load losses, runs cooler, and prioritizes fire safety without oils or fluids.
- 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 power distribution, power systems, distribution networks
- Power Rating 630kVA
- Certificate UL ,CESI, ISO
- Cooling Method OA/OF
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
630kVA Dry Type Transformer
Technical Specifications
Accessories
| 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
630kVA Dry Type Transformer
Our transformers offer a range of core features designed to meet diverse application needs and ensure reliable performance. The 630kVA Dry-Type Transformer provides reliable, efficient, and environmentally friendly power distribution. Key features include oil-free operation, advanced insulation for enhanced safety, low noise levels, and minimal maintenance. Its compact design makes it ideal for industrial and commercial applications, ensuring long-lasting, cost-effective performance. Tailor the 630kVA dry type transformer to exact voltage, load, and site specifications with broad customization for complex electrical networks. Primary voltages span 208V to 600V in delta or wye arrangements (e.g., 480V Delta, 240/480V dual-voltage, 600V), secondary voltages cover 208Y/120V, 480Y/277V, 240/120V, or custom low-voltage configurations, with vector groups like Dyn11 or Delta-Wye to support proper grounding, phase alignment, and harmonic mitigation.
Winding choices include aluminum for cost-optimized efficiency or copper for enhanced conductivity, lower losses, and greater thermal endurance. Temperature rise selections feature 150°C (standard), 115°C, or 80°C to improve efficiency and insulation longevity in elevated ambient or sustained high-load conditions, paired with 220°C or higher class insulation. Enclosure options provide ventilated NEMA 1 for indoor dry settings, NEMA 3R with weathershields for outdoor or humid exposure, or fully encapsulated for dust, moisture, corrosive, or hazardous classified areas. K-factor ratings (4, 9, 13, 20+) accommodate nonlinear loads from drives, servers, or electronics, while electrostatic shields reduce common-mode noise and transients.
Packing and Shipping
630kVA Dry Type Transformer
The 630kVA dry type transformer undergoes careful packaging to protect core, windings, enclosure, and components during handling and transit, taking advantage of its oil-free nature for reduced hazards and easier logistics. After final inspection, terminals insulate, taps set, enclosure latched, and unit cleaned prior to protective wrapping.
Transformer mounts securely on a heavy reinforced wooden pallet or skid for forklift access, enveloped in multi-layer stretch film, VCI paper to inhibit corrosion, and foam/corner guards shielding louvers, terminals, lifting eyes, and vulnerable protrusions. Ventilated models use breathable covers to permit airflow while excluding contaminants; encapsulated versions incorporate additional rigid bracing. Accessories (fans, weathershields, breakers) ship factory-mounted where possible or in separate labeled crates with cushioning.
Export packaging follows ISPM-15 heat-treated lumber standards, reinforced with steel strapping, edge protectors, and prominent markings for weight (typically 4500-6500 lbs / 2041-2948 kg), center of gravity, lift points (eyebolts/brackets), dimensions (approx. 85-105" H x 65-85" W x 55-75" D), and handling warnings ("Fragile Electrical Equipment - Specialized Lifting Required"). Tamper-evident seals secure access panels; weatherproof barriers protect connections.
Domestic transport employs enclosed trailers or flatbeds with secure tie-downs and blocking to prevent shifting or vibration damage. International shipments utilize 20ft/40ft containers (palletized, shrink-wrapped), air freight for expedited needs, or LCL arrangements, with certified lashing to withstand dynamic forces. GPS tracking provides real-time updates; full-value cargo insurance covers potential risks from origin to destination. Upon delivery, detailed installation guides cover safe lifting (via designated points), positioning with required ventilation clearances, grounding, torque values for terminations, and pre-energization checks (insulation resistance, turns ratio). Customs documentation—including commercial invoices, packing lists, certificates of origin, efficiency certifications, and test reports—facilitates prompt clearance. Pre-shipment third-party or customer witness inspections can be arranged for verification. Our logistics ensure full regulatory compliance, minimized transit risks, and arrival of a transformer ready for swift, secure integration.
Transformer mounts securely on a heavy reinforced wooden pallet or skid for forklift access, enveloped in multi-layer stretch film, VCI paper to inhibit corrosion, and foam/corner guards shielding louvers, terminals, lifting eyes, and vulnerable protrusions. Ventilated models use breathable covers to permit airflow while excluding contaminants; encapsulated versions incorporate additional rigid bracing. Accessories (fans, weathershields, breakers) ship factory-mounted where possible or in separate labeled crates with cushioning.
Export packaging follows ISPM-15 heat-treated lumber standards, reinforced with steel strapping, edge protectors, and prominent markings for weight (typically 4500-6500 lbs / 2041-2948 kg), center of gravity, lift points (eyebolts/brackets), dimensions (approx. 85-105" H x 65-85" W x 55-75" D), and handling warnings ("Fragile Electrical Equipment - Specialized Lifting Required"). Tamper-evident seals secure access panels; weatherproof barriers protect connections.
Domestic transport employs enclosed trailers or flatbeds with secure tie-downs and blocking to prevent shifting or vibration damage. International shipments utilize 20ft/40ft containers (palletized, shrink-wrapped), air freight for expedited needs, or LCL arrangements, with certified lashing to withstand dynamic forces. GPS tracking provides real-time updates; full-value cargo insurance covers potential risks from origin to destination. Upon delivery, detailed installation guides cover safe lifting (via designated points), positioning with required ventilation clearances, grounding, torque values for terminations, and pre-energization checks (insulation resistance, turns ratio). Customs documentation—including commercial invoices, packing lists, certificates of origin, efficiency certifications, and test reports—facilitates prompt clearance. Pre-shipment third-party or customer witness inspections can be arranged for verification. Our logistics ensure full regulatory compliance, minimized transit risks, and arrival of a transformer ready for swift, secure integration.
32
32 years of industry experience
Manufacturer Test
630kVA Dry Type Transformer
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
Factory acceptance tests (FAT) for the 630kVA dry type transformer comply with IEEE C57.12.01, C57.12.90, and DOE protocols to confirm full performance and compliance prior to shipment. Routine visual and mechanical inspections examine enclosure finish quality, weld integrity, nameplate accuracy, terminal connections, tap positions, and grounding continuity. Winding resistance testing across all taps at temperature-corrected values verifies conductor uniformity and alignment with design calculations. Turns ratio (TTR) verification on every tap position ensures ratio precision within 0.5% tolerance and correct vector group alignment. Polarity checks confirm specified connections. Insulation resistance (megger at 1000-2500V) evaluates winding-to-winding and ground paths for high megohm readings. Applied potential withstand applies one-minute power-frequency test voltage per insulation class without flashover or corona.
Routine Test - DC Insulation Resistance Test
Purpose of Testing
The purpose of DC insulation resistance testing is to measure the insulation resistance of a device by applying a DC voltage, thereby evaluating the health of the insulation material and the voltage withstand capability of the electrical device. This test helps detect potential insulation aging, moisture or damage, preventing electrical failures in the device.
Testing Equipment
Insulation resistance tester (e.g. Megger, Fluke, Hioki, Klein Tools, etc.)
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.)
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.)
Pre-Test Preparation
Make sure the device is properly grounded and fully discharged to prevent residual charge in the device from affecting the test results.
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.
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.
Test Progress
Connect the Test Instrument:
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 .
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 .
Measure and Record
Start the test and record the following parameters:
Insulation resistance value (MΩ)
Applied voltage
Ambient temperature and humidity during testing
Insulation resistance value (MΩ)
Applied voltage
Ambient temperature and humidity during testing
Temperature Correction
The measured insulation resistance values are corrected to a reference temperature (usually 20°C) for accurate evaluation.
Repeat Testing (if necessary)
Measure different windings (high voltage, medium voltage, low voltage) or each bushing separately, and conduct comparative analysis to ensure the insulation status of all parts.
Evaluation Criteria (Reference)
Insulation resistance ≥ 1000 MΩ (excellent)
500 MΩ ≤ Insulation resistance < 1000 MΩ (good)
100 MΩ ≤ Insulation resistance < 500 MΩ
Insulation resistance < 100 MΩ
500 MΩ ≤ Insulation resistance < 1000 MΩ (good)
100 MΩ ≤ Insulation resistance < 500 MΩ
Insulation resistance < 100 MΩ
Test standard
IEEE C57.12.01 & IEEE C57.12.91 (Dry-Type)
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
Ideal for large-scale commercial complexes, office high-rises, shopping malls, educational institutions, and hospitals requiring heavy-duty indoor power distribution without oil-related risks. Also excels in industrial plants, factories, and processing facilities with substantial loads, offering efficient 480V to 208Y/120V step-down, quiet operation, and enhanced fire safety in high-occupancy or ventilated areas.
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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