25kVA Single Phase Pad Mounted transformer
The 25kVA Single Phase Pad Mounted transformer with a power rating of 25 kVA, the high voltage of the transformer is 24940GRDY/14400×12470GRDY/7200V, which is a dual high voltage design. Customers can switch between 14.4kV and 7.2kV through a dual voltage switch according to the distribution line. There is a five-position voltage regulating switch on the high-voltage side, which can allow small changes in voltage within ±2 * 2 ½%.
The 25 kVA transformer comes complete with an oil level indicator and a 4-position load break switch, adding to its versatility and ease of maintenance.
- 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 480-240/240-120or customized
- H.V. Tap Range ± 2×2.5% HV taps or others
- Type Loop Feed or Radial Feed
- BIL 30/95kV
- Standards IEEE, CSA, NEMA, DOE
- Application ultilities, residential, commercial district
- Power Rating 25kVA
- Certificate UL/cUL ,CESI , CSA
- 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
25kVA Single Phase Pad Mounted transformer
Technical Specifications
Accessories
| Rated Power | 25 kVA |
| Rating Primary Voltage | 11950Delta or Customized |
| Secondary Voltage | 480-240V 240-120V 277V Customized |
| Frequency | 50/60Hz |
| Vector Group | Ii0,Ii6 |
| 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 | 135 kg |
| Total Weight | 360 kg |
| Outline Dimensions（L×W×H）in. | 1000×900×700(mm) |
| Lifting Lug | ELSP Fuse |
| Hinged Door | BAY-O-NET Fuse |
| Parking Bracket | Tap Changer |
| Tank Cover | Oil Level Gauge |
| L.V Bushing (4-Hole ) | Pressure Relief Valve |
| Two/Four Position Load break Switch | Vacuum Pressure Gauge |
| HV Grounding Copper Bar | Terminal Block |
| Temperature Indicator | Door Handle |
| H.V Bushing Well | Ground Strap |
| Grounding Copper Bar | Nameplate |
| 1"'Drain Valve With 3/8" Sampler | Non-PCB decal |
| 1" Upper Fill Valve Filter Press Connection | High Voltage Warning Signs |
Customization Optional
25kVA Single Phase Pad Mounted transformer
Customize the 25kVA single phase pad mounted transformer to align with specific underground residential demands through extensive configuration choices for safety and integration. Primary voltage selections span grounded wye from 2400V to 34500V, featuring common ratings like 4160GrdY/2400, 12470GrdY/7200, 24940GrdY/14400, or dual-voltage options, matched to secondary voltages including 120/240V, 240/480V, 277V, or tailored low-voltage outputs. Winding materials provide aluminum for lightweight cost savings or copper for better conductivity in residential applications. Enclosure styles offer dead-front ANSI compartmental with low-profile shrubline aesthetics or ranch runner compactness for landscape blending. Tap changers include 5-position external (±2x2.5%) for on-site regulation, while impedance adjusts from 2% to 5% for optimal fault handling. Protective features like bayonet fuses, expulsion links, lightning arresters, or wildlife guards mitigate risks, and natural ester fluids deliver enhanced fire safety and biodegradability over mineral oil.
These options improve energy efficiency, surge resilience, and pad compatibility, offering utilities a flexible transformer for underground residential power focused on reliability and compliance. Additional enhancements feature enclosure coatings for corrosion resistance in humid environments, reinforced bases for seismic areas, or accessory integrations such as oil temperature gauges, liquid level indicators, and secondary spade connectors for simplified connections. Bushing BIL ratings up to 125-150kV suit surge conditions, and core advancements further cut no-load losses. These broad customizations position the 25kVA single phase pad mounted transformer as an adaptable, high-value solution, ensuring seamless, standards-compliant distribution with minimized maintenance and operational costs in underground residential networks.
Packing and Shipping
25kVA Single Phase Pad Mounted 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 process for a 25kVA Single Phase Pad Mounted Transformer is designed to ensure secure and safe delivery to the customer. The transformer is carefully packed in a durable, weather-resistant wooden crate or metal container to protect it from physical damage, moisture, and environmental factors during transportation.
The packaging includes shock-absorbing materials such as foam or bubble wrap to prevent any movement that could cause damage to the transformer during transit.
For shipping, the transformer is typically transported by road, rail, or sea, depending on the destination. It is securely fastened to the shipping platform or pallet using straps or tie-downs to prevent movement during transportation.
The packaging is clearly labeled with appropriate handling instructions and safety warnings to ensure that all parties involved in the transportation process handle the transformer with care.
All necessary shipping documentation, including customs clearance forms, certificates of origin, and other required permits, are provided to comply with international shipping regulations. Upon arrival, the transformer is carefully inspected for any transit-related damage before installation.
This thorough packing and shipping process ensures that the 25kVA Single Phase Pad Mounted Transformer reaches its destination in optimal condition, ready for safe installation and reliable long-term operation.
For this purpose, the Packing and Shipping process for a 25kVA Single Phase Pad Mounted Transformer is designed to ensure secure and safe delivery to the customer. The transformer is carefully packed in a durable, weather-resistant wooden crate or metal container to protect it from physical damage, moisture, and environmental factors during transportation.
The packaging includes shock-absorbing materials such as foam or bubble wrap to prevent any movement that could cause damage to the transformer during transit.
For shipping, the transformer is typically transported by road, rail, or sea, depending on the destination. It is securely fastened to the shipping platform or pallet using straps or tie-downs to prevent movement during transportation.
The packaging is clearly labeled with appropriate handling instructions and safety warnings to ensure that all parties involved in the transportation process handle the transformer with care.
All necessary shipping documentation, including customs clearance forms, certificates of origin, and other required permits, are provided to comply with international shipping regulations. Upon arrival, the transformer is carefully inspected for any transit-related damage before installation.
This thorough packing and shipping process ensures that the 25kVA Single Phase Pad Mounted Transformer reaches its destination in optimal condition, ready for safe installation and reliable long-term operation.
32
32 years of industry experience
Manufacturer Test
25kVA Single Phase Pad Mounted transformer
Progress Test
NPC Electric manufactures pad-mounted transformers with strict quality control. The Progress Test for a 25kVA Single Phase Pad Mounted Transformer is conducted at various stages during the manufacturing process to ensure the transformer meets all technical specifications and quality standards. This includes testing of key components such as the core insulation, winding resistance, and dielectric strength. The transformer’s electrical components, such as bushings and tap changers, are also tested for proper functionality.
The progress tests assess the transformer’s ability to handle operational conditions, including load variations and voltage fluctuations, ensuring it performs efficiently and safely. Any issues identified during these tests are addressed promptly, ensuring that the transformer is fully optimized and ready for the final Factory Acceptance Test (FAT).
The progress test guarantees that the 25kVA Single Phase Pad Mounted Transformer is built to the highest standards of reliability and safety before final delivery.
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)
♦ Lightning Impulse
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)
Transformer Factory Acceptance Test
NPC Electric will tests made for quality control by the manufacturer on every device or representative samples, or on parts or materials as required, to verify during production that the product meets the design specifications.
The Transformer Factory Acceptance Test (FAT) for a 25kVA Single Phase Pad Mounted Transformer is a crucial procedure conducted to verify that the transformer meets all required specifications and industry standards before it is shipped to the customer. The FAT typically includes the following key tests: Visual and Mechanical Inspection: Ensuring proper assembly, verifying that all components are correctly installed, and checking for any physical defects or damage. Electrical Testing: This involves measuring winding resistance, insulation resistance, and conducting a turns ratio test to confirm the electrical integrity of the transformer. Dielectric Testing: Applying high voltage to test the transformer’s insulation system to ensure it can withstand normal operating and transient voltages. Load and Performance Testing: Simulating operational conditions to assess the transformer’s performance under load, including checking voltage regulation and efficiency. The FAT ensures that the 25kVA Single Phase Pad Mounted Transformer is fully functional, safe, and ready for reliable operation, providing peace of mind for the customer upon delivery.
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)
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.
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).
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
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.
Application
Suitable for rural or low-density areas paired with small properties, this 25kVA single phase pad mounted transformer supports cabins, farms, pumps, or security loads, providing efficient, secure underground distribution in regions favoring minimal overhead visibility and reliable single-phase supply.
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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