250kVA Dry Type Cast Resin Transformer 10kV/0.4kV Copper Core | CE/IEC/UL
Introducing the premium 250kVA Dry Type Cast Resin Transformer 10kV/0.4kV Copper Core, a high-performance, maintenance-free solution engineered for safe and efficient indoor power distribution. Featuring fully vacuum-cast epoxy resin windings with premium copper conductors, this three-phase transformer delivers exceptional low-loss performance, reduced no-load and load losses, and outstanding energy efficiency often surpassing 98%. The cast resin encapsulation provides superior moisture resistance, fire self-extinguishing properties, and high partial discharge immunity, eliminating risks associated with oil-filled units. With natural air (AN) cooling, low noise levels, Class F/H insulation, and robust short-circuit withstand capability, it ensures reliable operation in demanding environments. Certified to CE, IEC 60076-11, and UL equivalents where applicable, this compact dry-type transformer supports primary 10kV (with ±2×2.5% off-circuit taps) to secondary 0.4kV transformation, ideal for modern sustainable electrical infrastructures prioritizing safety, energy savings, and environmental compliance.
- Primary Voltage Ratings 10 kV (10000 V) delta or grounded wye
- Secondary Voltage Ratings 0.4 kV (400/230 V) or 0.415 kV (415/240 V) wye
- 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 office buildings, transportation facilities
- Power Rating 250kVA
- Certificate IEC 60076-11, IEC 60076-1, IEC 60076-3, UL 1561
- Cooling Method OA/OF
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
250kVA Dry Type Cast Resin Transformer 10kV/0.4kV Copper Core | CE/IEC/UL
Technical Specifications
Accessories
| Rated Power | 250 kVA | |
| Rating Primary Voltage | 2.4-35kV | |
| 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 | |
|
Enclosure |
IP23 ventilated (indoor standard), IP54/IP55 totally enclosed (optional) |
|
|
Winding material |
Full high-conductivity copper (HV & LV) for maximum efficiency and lowest hot-spot temperatures |
|
| HV Bushing |
| LV Bushing |
| Tap changer connector |
| Lifting hook for complete transformer |
| Name plate |
Customization Optional
250kVA Dry Type Cast Resin Transformer 10kV/0.4kV Copper Core | CE/IEC/UL
The 250kVA Dry Type Cast Resin Transformer 10kV/0.4kV Copper Core offers extensive customization to meet precise project specifications, environmental conditions, and regulatory needs in indoor power systems. Primary voltage options span 6kV to 35kV (including 10kV, 11kV, 20kV), with secondary voltages such as 0.4kV, 0.69kV, or custom low-voltage outputs. Copper windings ensure maximum conductivity, but aluminum alternatives are available for cost optimization. Tap changers include off-circuit ±2×2.5% or ±5% for standard regulation, with on-load tap changer (OLTC) upgrades for automatic voltage stabilization in variable-load scenarios. Insulation classes upgrade to Class H (180°C) for higher ambient temperatures or overload demands, while partial discharge can be limited below 5pC for ultra-sensitive installations. Cooling enhancements feature forced air (AF) fans for increased capacity and overload handling up to 150%, alongside IP23 to IP54 enclosure ratings for dust/moisture protection.
Additional personalization includes vector groups (Dyn11, Yyn0, or custom) for harmonic suppression and parallel running compatibility, integrated PT100 temperature sensors with digital monitoring relays, anti-vibration pads for noise reduction below 55dB, and special resin formulations for enhanced fire behavior (F1 class) or environmental resistance. Smart features like Modbus/RS485 interfaces enable predictive maintenance and IoT integration. These flexible options allow seamless adaptation to commercial, industrial, or renewable setups, making the transformer highly visible in searches for "customizable copper core 250kVA cast resin dry type transformers."
Packing and Shipping
250kVA Dry Type Cast Resin Transformer 10kV/0.4kV Copper Core | CE/IEC/UL
Packaging for the 250kVA Dry Type Cast Resin Transformer prioritizes safeguarding the resin-encapsulated windings and core during global transport. The unit is firmly secured to a reinforced wooden pallet with anti-vibration mounts, protective corner braces, and lifting lugs for safe handling. Exposed terminals and sensors are individually shielded with foam inserts and rigid caps, while the entire assembly is enveloped in multi-layer anti-static, moisture-resistant film. A custom export-grade wooden crate, treated to ISPM 15 standards, fully encloses the transformer with internal padding, humidity indicator plugs, and shock/tilt recorders to monitor transit conditions, ensuring the dry-type design arrives pristine and installation-ready.
Shipping solutions are flexible and secure, accommodating diverse project timelines for this compact cast resin unit. Ocean freight via 20ft or 40ft containers offers economical international delivery with secure blocking and bracing, typically 20-50 days to major ports. Air cargo expedites urgent needs in 5-10 days. Domestic/regional transport uses enclosed or flatbed trucks with weather protection and secure tie-downs, complying with road regulations. Full-value cargo insurance protects against any transit risks.
Complete export documentation—including commercial invoices, packing lists, origin certificates, test reports, and CE/IEC/UL compliance declarations—facilitates swift customs processing. Sustainable practices incorporate recyclable materials and optimized routing to minimize environmental impact. Real-time tracking portals provide GPS updates and coordinator support from origin to destination.
Upon arrival, optional services include supervised unpacking, final insulation resistance checks, and packaging disposal/recycling to speed commissioning. Bulk orders benefit from consolidated shipments and phased delivery scheduling. This comprehensive approach guarantees flawless delivery, optimizing visibility for "reliable cast resin dry type transformer shipping."
Shipping solutions are flexible and secure, accommodating diverse project timelines for this compact cast resin unit. Ocean freight via 20ft or 40ft containers offers economical international delivery with secure blocking and bracing, typically 20-50 days to major ports. Air cargo expedites urgent needs in 5-10 days. Domestic/regional transport uses enclosed or flatbed trucks with weather protection and secure tie-downs, complying with road regulations. Full-value cargo insurance protects against any transit risks.
Complete export documentation—including commercial invoices, packing lists, origin certificates, test reports, and CE/IEC/UL compliance declarations—facilitates swift customs processing. Sustainable practices incorporate recyclable materials and optimized routing to minimize environmental impact. Real-time tracking portals provide GPS updates and coordinator support from origin to destination.
Upon arrival, optional services include supervised unpacking, final insulation resistance checks, and packaging disposal/recycling to speed commissioning. Bulk orders benefit from consolidated shipments and phased delivery scheduling. This comprehensive approach guarantees flawless delivery, optimizing visibility for "reliable cast resin dry type transformer shipping."
32
32 years of industry experience
Manufacturer Test
250kVA Dry Type Cast Resin Transformer 10kV/0.4kV Copper Core | CE/IEC/UL
Progress Test
Early manufacturing stages for the 250kVA dry type cast resin transformer focus on core validation through precise Epstein frame measurements of specific losses in grain-oriented silicon steel to ensure ultra-low no-load performance. Copper winding coils undergo automated layer winding with real-time high-potential surge testing between turns for insulation uniformity and defect elimination. Pre-casting conductor positioning is verified via laser alignment for optimal spacing and duct placement. Initial vacuum pressure impregnation monitors resin flow and void detection using ultrasonic scanning. Core-coil assembly includes low-voltage excitation for magnetization curve profiling and harmonic analysis. These foundational checks, digitally logged with component serialization, build a robust base for energy-efficient and reliable operation. Mid-to-late progress evaluations feature controlled resin casting with temperature-monitored curing cycles and hardness testing to confirm encapsulation integrity. Partial discharge pre-testing during voltage ramp-up identifies anomalies below strict thresholds.
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
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
Transformer Factory Acceptance Test
Factory Acceptance Testing for the 250kVA dry type cast resin transformer begins with accurate ratio and polarity verification across taps using precision ratiometric instruments, confirming 10kV/0.4kV transformation within tight tolerances. No-load loss and excitation current measurements at rated and over/under voltages validate core efficiency and low magnetizing demand. Winding resistance is determined at reference temperature for precise load loss computation. Dielectric routine tests encompass applied voltage withstand at specified levels and insulation resistance far exceeding minimums. Partial discharge assessment under induced overvoltage restricts levels to low pC values. These essential electrical validations, fully documented and optionally witnessed, establish core performance and safety per IEC 60076-11. Advanced FAT includes temperature rise testing at rated load with sensor monitoring, keeping average winding rises within Class F/H limits (typically 100K/125K).
Routine Test - Induced Voltage
Purpose of Testing
The purpose of winding resistance testing is to detect the continuity and connection quality of the internal conductors of the motor or transformer windings, and to promptly detect potential faults such as open circuits, poor contact or local heating.
Testing Equipment
Induced Voltage Tester (e.g. OMICRON, Megger, HioKI, etc.)
AC voltage source, commonly 2 kV, 5 kV, 10 kV, or customized according to test requirements.
Environmental thermometer and hygrometer, used to record the temperature and humidity of the environment for appropriate test evaluation.
AC voltage source, commonly 2 kV, 5 kV, 10 kV, or customized according to test requirements.
Environmental thermometer and hygrometer, used to record the temperature and humidity of the environment for appropriate test evaluation.
Pre-Test Preparation
Disconnect all relevant power supplies and ensure that the equipment is properly grounded and discharged.
Check the connection wires and terminals to ensure they are secure and free of contamination.
Test under suitable environmental conditions: relative humidity below 75%, no rain (recommended temperature: 20-30°C).
Check the connection wires and terminals to ensure they are secure and free of contamination.
Test under suitable environmental conditions: relative humidity below 75%, no rain (recommended temperature: 20-30°C).
Test Progress
Connect the Test Instrument:
Connect the test equipment to the appropriate terminals or bushings of the device under test, ensuring that the connections are secure and properly grounded.
Apply Test Voltage:
Select the appropriate induction voltage according to the rated voltage and standard of the equipment.
Connect the test equipment to the appropriate terminals or bushings of the device under test, ensuring that the connections are secure and properly grounded.
Apply Test Voltage:
Select the appropriate induction voltage according to the rated voltage and standard of the equipment.
Measure and Record
Start the test and record the following parameters:
Induced Voltage
Applied Current
Voltage peak, stability and waveform (waveform analysis)
Any abnormal current or voltage changes during the measurement process.
Induced Voltage
Applied Current
Voltage peak, stability and waveform (waveform analysis)
Any abnormal current or voltage changes during the measurement process.
Temperature Correction
The measured induced voltage data is corrected to the reference temperature (usually 20°C) to ensure the accuracy of the test results.
Repeat Testing (if necessary)
If necessary, test different windings (HV, MV, LV) and bushings separately and compare the results at different test points.
Evaluation Criteria (Reference)
Inductive voltage ≤ 1% (Excellent): normally and meets safety standards.
1% < Inductive voltage ≤ 3% (Good): still within acceptable range.
Inductive voltage > 3% : faulty or not meet safety requirements and requires further analysis and repair.
1% < Inductive voltage ≤ 3% (Good): still within acceptable range.
Inductive voltage > 3% : faulty or not meet safety requirements and requires further analysis and repair.
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
Widely applied in mixed-use complexes, light manufacturing facilities, and public infrastructure, delivering energy-efficient, fire-safe power for integrated commercial, institutional, and small industrial operations. Perfect for commercial offices, retail malls, and high-rise buildings, offering safe, quiet indoor power distribution without oil hazards near occupied spaces.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
Transformers Packaging (1)
Transformers Packaging (2)
Transformers Packaging (3)
Transformers Packaging (4)
Transformers Packaging (5)
Transformers Packaging (6)
Transformers Packaging (7)
Transformers Packaging (8)
Related Products
300kVA Three Phase Pad Mounted Transformer
The 300kVA three-phase pad transformer is an efficient and reliable power device designed for commercial, industrial and distribution systems. The transformer provides a high power capacity of 300kVA, which can provide a stable three-phase power supply for high-load equipment, ensuring efficient and smooth operation of the power system. Its sturdy housing adopts a protective design that meets the NEMA 3R standard, which can effectively resist the invasion of the external environment and is suitable for outdoor installation.
100kVA Single Phase Pad Mounted Transformer
The 100 kVA Single Phase Pad Mounted transformer adheres to a compartmental-type structure in line with IEEE Std C57.12.28 or IEEE Std C57.12.29 standards. It consists of a tank housing high-voltage and low-voltage cable terminating compartments, thoughtfully positioned side by side along one face of the transformer tank. In this configuration, the high-voltage compartment, fitted with two internally connected high-voltage bushing wells and inserts, a 4-position loadbreak switch, a 5-position tap changer switch, and a bayonet fuse, is situated alongside the low-voltage compartment featuring three stud L.V bushings and an oil level gauge.
7500kVA Dry Type Transformer
7500kVA Dry Type Transformer is a high-capacity, reliable power solution designed for large-scale industrial and commercial applications. With a robust 7500kVA rating, it incorporates advanced dry-type insulation technology, ensuring enhanced safety, minimal maintenance, and exceptional durability. Engineered for demanding environments, this transformer delivers stable, efficient, and low-noise operation while reducing environmental impact. The NPC ELECTRIC 7500kVA Dry Type Transformer is the ideal choice for high-power applications, providing secure and continuous power distribution for critical infrastructure. Typical attributes encompass three-phase construction, primary voltages 208V–600V (e.g., 480V Delta, 600V Delta), secondary voltages such as 208Y/120V, 480Y/277V, or custom, aluminum or copper windings, 150°C rise (standard) or 115°C/80°C with 220°C insulation class, ±2×2.5% primary taps, NEMA 1 ventilated enclosure (NEMA 3R/encapsulated options), natural convection cooling (AN), electrostatic shielding, and low sound levels per NEMA.
200kVA Single Phase Pole Mounted Transformer
NPC ELECTRIC'S 200kVA single phase pole mounted transformer delivers exceptional reliability for demanding overhead power systems. It efficiently converts primary voltages like 11kV or 22kV to secondary levels such as 220V or 400V, supporting heavier loads in diverse environments. Constructed with low-loss grain-oriented steel cores and high-grade aluminum conductors, it achieves superior energy efficiency and reduced operational costs. Meeting ANSI/IEEE C57 standards, the weatherproof enclosure ensures protection against elements, with a 55°C temperature rise and ONAF cooling for enhanced performance. Essential safety integrations include overload fuses and oil level gauges, making it suitable for utilities aiming for minimal downtime. This transformer excels in providing stable power with low harmonic distortion, ideal for modern grid upgrades.
250kVA Single Phase Pole Mounted Transformer
Engineered for heavy-duty overhead applications, the 250kVA single phase pole mounted transformer provides dependable voltage transformation from primary levels like 12.47kV, 24.94kV, or 34.5kV to secondary outputs such as 120/240V or 277/480V. Featuring grain-oriented silicon steel cores for minimal core losses and robust windings, it achieves high efficiency while adhering to DOE energy standards and IEEE C57.12.20 guidelines. The corrugated tank design promotes superior heat dissipation, paired with ONAN self-cooling and a 65°C temperature rise for sustained performance under peak demands. Weather-resistant construction includes lifting lugs, pressure relief devices, and surge protection options, ensuring longevity in exposed environments. This transformer minimizes maintenance needs and supports stable power supply with low noise and excellent overload capability, making it a preferred choice for expanding grid infrastructure.
200kVA Oil Immersed Transformer
The 200kVA oil-immersed transformer produced by our company adopts a new insulation structure to improve the short-circuit resistance; the iron core is made of high-quality cold-rolled silicon steel sheet; the high-voltage winding is made of high-quality oxygen-free copper wire and adopts a multi-layer cylindrical structure; all fasteners are treated with special anti-loosening treatment. Standard configuration includes mineral oil or FR3 natural ester fluid, ONAN cooling, aluminum or copper windings, high-voltage 34.5kV / 24.94kV / 13.8kV / 12.47kV / 4.16kV.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