1250kVA Single Phase Pad Mounted Transformer
The 1250kVA Single Phase Pad Mounted Transformer is a premium solution crafted for expansive underground electrical systems in high-growth areas. Housed in a secure, weatherproof cabinet with advanced dead-front or live-front configurations, it maximizes personnel safety and deters tampering in public spaces. Adhering to ANSI C57.12.25, IEEE C57.12.91, and energy efficiency mandates, this 1250kVA single-phase padmount excels in transforming primary voltages up to 34.5kV to flexible secondary levels, offering exceptional short-circuit strength and quiet operation for large-scale residential and commercial deployments.
- Primary Voltage Ratings 34.5-19.92/13.8-7.957/13.2-7.62/12.47-7.2 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 expansive retail malls, university campuses, and medical centers
- Power Rating 1250kVA
- 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
1250kVA Single Phase Pad Mounted Transformer
Technical Specifications
Accessories
| Rated Power | 1250kVA |
| 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
1250kVA Single Phase Pad Mounted Transformer
The 1250kVA Single Phase Pad Mounted Transformer stands out with exceptional customization potential, allowing precise adaptation to sophisticated underground infrastructure needs. Primary voltage capabilities extend from 4.8kV to 46kV with robust BIL ratings up to 250kV for superior surge withstand, complemented by secondary outputs such as 120/240V, 480Y/277V, or custom high-current configurations for heavy loads. Choose premium copper windings for enhanced conductivity and extended lifespan or aluminum for streamlined handling and economic advantages. High-voltage setups incorporate sophisticated eight-position switching, visible-load-break mechanisms, or integrated expulsion and current-limiting fuse systems, paired with hold-down cleats and arrester combos for optimized protection. Low-voltage sections feature expandable buswork and multiple connection points to support future upgrades seamlessly.
Specialized enhancements include fully stainless steel construction with marine-grade finishes, low-viscosity silicone or beta fluids for extreme temperature resilience, and smart diagnostic packages with oil quality analyzers and remote communication modules. Additional options encompass nitrogen cushioning, fault passage indicators, custom labeling with QR codes, and high-impact polycarbonate windows. Impedance adjustments (2.5-8%) facilitate precise coordination, while coastal or pollution-resistant coatings ensure durability. These tailored specifications position the unit as a prime option for "bespoke high-capacity single-phase pad-mounted transformers" in advanced utility engineering.
Packing and Shipping
1250kVA Single Phase Pad Mounted Transformer
Delivering the substantial 1250kVA Single Phase Pad Mounted Transformer safely demands precision-engineered packaging that addresses its size and critical components. The unit is rigidly fixed to an oversized, kiln-dried wooden skid reinforced with steel cross-bracing and anti-shift blocks to neutralize transport vibrations. Bushings and connectors are protected with rigid polymer covers and internal bracing struts, while the cabinet is fully encased in multi-ply vapor-barrier film and edge-protected foam sheeting. A custom-built, ISPM 15-certified wooden crate with integrated lifting beams and forklift channels provides complete enclosure, augmented by active humidity monitors, triple-axis shock loggers, and desiccant saturation indicators to safeguard the sealed oil system throughout the journey.
Shipping strategies are comprehensively tailored for this heavyweight padmount, ensuring secure and timely global distribution. Maritime transport employs 40ft platform or high-cube containers with engineered cradles and multi-point lashing certified for heavy cargo, facilitating reliable 30-65 day deliveries to international destinations. Priority air freight charters accommodate emergency needs with 7-15 day turnaround for swift restoration. Regional hauls utilize specialized extendable trailers equipped with air suspension and real-time GPS monitoring, complete with route surveys and permits for seamless oversized movement.
Export compliance is streamlined through pre-compiled documentation packs, including origin declarations, weight certificates, and specialized fluid handling advisories for efficient port processing. Green logistics incorporate recycled crate components and voyage optimization tools to curtail emissions. Customers access a proprietary portal for continuous shipment visibility, predictive ETAs, and expert coordination.
Arrival protocols feature optional synchronized unloading with mobile cranes, thorough transit impact reviews, and sustainable packaging reclamation to enable rapid site preparation. Volume procurements benefit from phased container scheduling and cost-sharing consolidations. This elite packing and shipping service ensures your 1250kVA transformer is delivered in factory-fresh condition, dominating searches for "professional large pad-mounted transformer delivery."
Shipping strategies are comprehensively tailored for this heavyweight padmount, ensuring secure and timely global distribution. Maritime transport employs 40ft platform or high-cube containers with engineered cradles and multi-point lashing certified for heavy cargo, facilitating reliable 30-65 day deliveries to international destinations. Priority air freight charters accommodate emergency needs with 7-15 day turnaround for swift restoration. Regional hauls utilize specialized extendable trailers equipped with air suspension and real-time GPS monitoring, complete with route surveys and permits for seamless oversized movement.
Export compliance is streamlined through pre-compiled documentation packs, including origin declarations, weight certificates, and specialized fluid handling advisories for efficient port processing. Green logistics incorporate recycled crate components and voyage optimization tools to curtail emissions. Customers access a proprietary portal for continuous shipment visibility, predictive ETAs, and expert coordination.
Arrival protocols feature optional synchronized unloading with mobile cranes, thorough transit impact reviews, and sustainable packaging reclamation to enable rapid site preparation. Volume procurements benefit from phased container scheduling and cost-sharing consolidations. This elite packing and shipping service ensures your 1250kVA transformer is delivered in factory-fresh condition, dominating searches for "professional large pad-mounted transformer delivery."
32
32 years of industry experience
Manufacturer Test
1250kVA Single Phase Pad Mounted Transformer
Progress Test
Fabrication of the 1250kVA single-phase pad-mounted transformer begins with rigorous core evaluation, utilizing advanced hysteresis loop tracing and no-load loss quantification on step-lap assemblies to achieve elite efficiency metrics. Winding development employs precision tension control systems with embedded high-voltage pulse monitoring to eradicate interlayer defects and ensure current density equilibrium. Cabinet engineering integrates 3D structural simulation and weld seam electron beam analysis for uncompromised strength and weather sealing. Preliminary active part integration conducts low-flux harmonic analysis and magnetic balance testing to preempt operational imbalances. Tank preparation includes multi-stage vacuum integrity verification and helium mass spectrometry for microscopic leak detection. Accessory pre-mounting validates torque sequences and electrical isolation on high-voltage interfaces. Serialized data capture via integrated manufacturing execution systems guarantees component-level accountability and quality progression from initial build phases.
Design Tests
All transformer 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)
♦ Applied Voltage
♦ Induced 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. Sophisticated continuation features over-frequency induced testing with acoustic and UHF partial discharge localization, capping apparent charge below 30pC for assured long-term reliability. Efficiency and regulation profiling utilizes calibrated load simulation to quantify performance at unity and lagging power factors. Mechanical endurance validation executes thousands of switching operations, confirming load interruption ratings and visible isolation compliance. Protective device coordination trials trigger fuses and relays under controlled fault magnitudes. Comprehensive heat run under compounded loading profiles monitors stratified temperatures via real-time fiber-optic arrays, verifying compliance with hotspot allowances. Noise emission characterization employs precision sound intensity mapping in hemi-anechoic conditions for community-compatible results. Concluding holistic audit inspects enclosure ingress protection, grounding effectiveness, finish durability, and accessory synchronization. Exhaustive reporting—with thermal imaging, waveform archives, and formal sign-off—accompanies the unit, fully endorsing its deployment in mission-critical large-scale underground infrastructure.
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
Predominantly utilized in large-scale master-planned urban districts and technology parks blending housing with commercial spaces, providing robust underground supply for integrated living-working ecosystems through advanced loop-feed architectures.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
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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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