500kVA Single Phase Pad Mounted Transformer
The 500kVA Single Phase Pad Mounted Transformer is a high-capacity electrical transformer designed for reliable and efficient power distribution in commercial, industrial, and utility applications. With a robust, weatherproof enclosure, it is specifically built for outdoor use and can handle the demanding requirements of larger single-phase systems. This transformer offers a 500kVA capacity, ensuring dependable performance for a variety of load conditions.
- 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, ANSI, CSA
- Application Utility, Residential areas, Commercial hubs
- Power Rating 500kVA
- Certificate UL/cUL, CSA, CESI
- 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
500kVA Single Phase Pad Mounted Transformer
Technical Specifications
Accessories
| Rated Power | 500 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 | 620 kg |
| Total Weight | 3650 kg |
| Outline Dimensions（L×W×H）in. | 1500×1200×1800(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
500kVA Single Phase Pad Mounted Transformer
NPC ELECTRIC’s single-phase pad-mounted transformers can be fully customized to meet your specific requirements. The 500kVA single-phase pad-mounted transformer has a rich range of optional specifications. In terms of voltage, the primary input voltage can be selected from a variety of common voltage levels such as 6.6kV, 11kV, and 22kV as needed, and the secondary output voltage has different standards such as 230V, 400V, and 480V to adapt to different power-consuming equipment and power grid requirements. In terms of tap changers, there are two options: off-excitation tap changers and on-load tap changers. On-load tap changers can adjust the voltage without shutting down the transformer, which can cope with frequent load changes; off-excitation tap changers are suitable for relatively stable voltage conditions.
In terms of insulation system, A-class, F-class or H-class insulation materials can be selected. Among them, H-class insulation allows higher winding temperature, which can improve the overload capacity and service life of the transformer. The oil tank material can be selected from ordinary carbon steel or stainless steel. Stainless steel has better corrosion resistance and is suitable for installation in coastal areas or chemical industries with high corrosion risks.
Packing and Shipping
500kVA Single Phase Pad Mounted Transformer
Preparation for the 500kVA single phase pad mounted transformer emphasizes protection and compliance for secure global transport. Pre-packing procedures involve detailed inspections, including dielectric oil testing (when shipped filled), nitrogen blanketing for dry shipments to avoid moisture or oxidation, and protective capping/shielding of bushings, gauges, valves, and fittings with durable foam or rigid guards against vibration and impact. The tank and enclosure receive corrosion-inhibiting coatings, temporary wraps on exposed surfaces, and secure fastening of all accessories to prevent shifting during handling.
Packing utilizes heavy-duty wooden crates or reinforced skids custom-built to the transformer's footprint, incorporating steel banding, internal bracing, and load-distributing blocks to handle the substantial weight (typically 3200–3800 lbs dry, higher oil-filled). Export crates adhere to ISPM 15 heat-treatment standards for phytosanitary compliance, supplemented by vapor barriers, desiccant packs, and humidity monitoring devices. Oil-filled units feature enhanced sealing around bushings and valves, absorbent materials for potential leaks, and full adherence to hazardous goods regulations (e.g., UN classifications for insulating fluids), complete with appropriate placards and documentation.
Shipping arrangements prioritize safety and timeliness, with domestic North American transport via specialized heavy-equipment carriers using lowboy trailers, secure ratchet tie-downs, and pilot/escort vehicles for oversize loads when necessary. International shipments employ multimodal options: road to port, ocean freight in 40ft open-top or flat-rack containers (or break-bulk for bulk orders), and final inland delivery. Comprehensive insurance, GPS-enabled tracking, and detailed manifests provide full visibility. Prominent markings include lift points, center-of-gravity indicators, and handling directives to facilitate safe crane or forklift operations throughout transit.
Upon receipt, conduct thorough visual inspections for transit damage, confirm seal integrity, oil levels, and accessory condition before unloading. Use professional rigging equipment with spreader beams to prevent tank stress or misalignment. Our logistics team offers complete assistance, including freight rate coordination, export documentation (invoices, certificates of origin, test reports, packing lists), and customs support to expedite clearance, ensuring the transformer arrives ready for immediate pad installation, cabling, and commissioning with minimal disruption.
Packing utilizes heavy-duty wooden crates or reinforced skids custom-built to the transformer's footprint, incorporating steel banding, internal bracing, and load-distributing blocks to handle the substantial weight (typically 3200–3800 lbs dry, higher oil-filled). Export crates adhere to ISPM 15 heat-treatment standards for phytosanitary compliance, supplemented by vapor barriers, desiccant packs, and humidity monitoring devices. Oil-filled units feature enhanced sealing around bushings and valves, absorbent materials for potential leaks, and full adherence to hazardous goods regulations (e.g., UN classifications for insulating fluids), complete with appropriate placards and documentation.
Shipping arrangements prioritize safety and timeliness, with domestic North American transport via specialized heavy-equipment carriers using lowboy trailers, secure ratchet tie-downs, and pilot/escort vehicles for oversize loads when necessary. International shipments employ multimodal options: road to port, ocean freight in 40ft open-top or flat-rack containers (or break-bulk for bulk orders), and final inland delivery. Comprehensive insurance, GPS-enabled tracking, and detailed manifests provide full visibility. Prominent markings include lift points, center-of-gravity indicators, and handling directives to facilitate safe crane or forklift operations throughout transit.
Upon receipt, conduct thorough visual inspections for transit damage, confirm seal integrity, oil levels, and accessory condition before unloading. Use professional rigging equipment with spreader beams to prevent tank stress or misalignment. Our logistics team offers complete assistance, including freight rate coordination, export documentation (invoices, certificates of origin, test reports, packing lists), and customs support to expedite clearance, ensuring the transformer arrives ready for immediate pad installation, cabling, and commissioning with minimal disruption.
32
32 years of industry experience
Manufacturer Test
500kVA Single Phase Pad Mounted Transformer
Progress Test
Progress tests during production of the 500kVA single phase pad mounted transformer verify quality at sequential stages. Core construction checks encompass lamination alignment, clamping torque, and insulation resistance between sheets to achieve low core losses and structural integrity. Winding processes include conductor insulation verification, precise turn placement, layer-by-layer continuity testing, and tension monitoring for uniform coils. After core-coil assembly, preliminary insulation resistance, hipot withstand, and core grounding tests detect issues early. Tank fabrication progress involves weld inspections via ultrasonic or dye penetrant, hydrostatic leak testing, surface blasting/prep evaluation, and primer thickness gauging. Final assembly stages feature bushing installation torque checks, accessory mounting alignment, gasket seal compression, and controlled fluid filling or dry-out monitoring to maintain purity and prevent ingress. Impedance and preliminary load loss evaluations ensure design conformance. Enclosure checks include door functionality, latch security, tamper-proof feature validation, paint thickness and adhesion testing. Fluid-related tests sample dielectric strength and moisture if processed early.
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)
♦ Lightning Impulse
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)
Transformer Factory Acceptance Test
Dielectric tests comprise applied potential and induced voltage withstand at elevated levels, ensuring no breakdown or excessive partial discharge. Impedance voltage and load loss measurements under short-circuit simulate operational conditions, validating against guaranteed parameters. Oil dielectric breakdown, moisture, and acidity tests apply for fluid-filled units. Functional verifications test fuse operation, pressure relief device activation, gauge accuracy, valve integrity, and bushing performance. Optional evaluations like sound level metering, heat run simulation, or impulse testing occur as specified. All data compiles into certified reports, available for client or third-party witnessing, confirming adherence to IEEE C57.12.00, C57.12.38, ANSI, and efficiency standards prior to shipment approval, guaranteeing exceptional reliability and performance in service. Polarity, phase relation, and vector confirmation use low-voltage methods. DC winding resistance is measured and corrected to reference temperature. No-load loss, excitation current, and efficiency metrics are recorded at rated voltage to confirm DOE 2016 compliance and low noise operation.
Routine Test - Induced Voltage
Purpose of Testing
The purpose of the Induced Voltage test is to simulate the electrical stress that the equipment may encounter under actual working conditions by applying an induced voltage, thereby evaluating the tolerance and stability of the equipment's insulation system. This test helps to detect the insulation performance of the equipment under high voltage conditions and ensure its safety and reliability in operation.
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.
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
Well-suited for commercial districts, industrial parks, schools, hospitals, transportation hubs like rail stations or ports, and utility grid expansions in urban settings; seamlessly combines with heavy EV charging networks, solar/wind renewable tie-ins, data centers, and mixed-use complexes demanding robust, tamper-proof, high-efficiency single-phase underground distribution for critical and variable loads.
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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