800kVA Three Phase Pad Mounted Transformer
NPC ELECTRIC's 800kVA three phase pad mounted transformer provides exceptional power handling for high-demand medium-voltage applications, ensuring stable and efficient distribution in outdoor settings. Built with safety and longevity in mind, this pad-mounted unit features three-point door latching, automatic pressure relief, liquid level/pressure/vacuum gauges, high BIL ratings (up to 150kV for surge protection), and a tamper-resistant structure suitable for public access areas. Its compact, low-profile footprint facilitates easy installation on concrete pads in constrained urban or industrial sites, while advanced enclosure integrity meets IEEE C57.12.28 requirements.
- Primary Voltage Ratings 34.5-19.92/13.8-7.957/13.2-7.62/12.47-7.2 or others
- Secondary Voltage Ratings 208GrdY/120;416GrdY/240 or Customized
- H.V. Tap Range ± 2×2.5% HV taps or others
- Type Loop Feed or Radial Feed
- BIL 30/95kV
- Standards IEEE, ANSI, NEMA, ASTM
- Application extensive commercial developments, high-rise offices, retail centers
- Power Rating 800kVA
- Certificate UL
- 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
800kVA Three Phase Pad Mounted Transformer
Technical Specifications
Accessories
| Rated Power | 800kVA |
| Rating Primary Voltage | 4.16-34.5kV or customized |
| Secondary Voltage | 480GrdY/277 208GrdY/120 400GrdY/230 Customized（208Y/120 V to 4,160 V） |
| Frequency | 50/60Hz |
| Vector Group | Dyn1/Yyn0/Dyn11/Dyn5 |
| Winding Material | Aluminum/Copper |
| Efficiency | As IEEE,Doe 2016,CAS Std or Customized |
| Impedance Voltage | Nominal 3.5% 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 | 3500 kg |
| Total Weight | 9700 kg |
| Outline Dimensions（L×W×H）in. | 2880×2200×2100（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(15kV) | Ground Strap |
| Grounding Copper Bar | Nameplate |
| 1"'Drain Valve With 3/8" Sampler | IR Window |
| 1" Upper Fill Valve Filter Press Connection | Terminal Box |
| Non-PCB decal | High Voltage Warning Signs |
Customization Optional
800kVA Three Phase Pad Mounted Transformer
Adapt the 800kVA three phase pad mounted transformer to your precise operational needs with extensive customization capabilities across electrical, mechanical, and environmental parameters. Select primary voltages from 2400Δ to 34500GrdY/19920, secondary outputs from 208Y/120V to 600Y/347V or higher, including dual-voltage arrangements and adjustable tap configurations (e.g., extended ranges or NEMA-specific taps) for optimal regulation during load fluctuations. Configure high-voltage terminations as dead-front (200A/600A interfaces) or live-front, radial or loop feed layouts, and insulating medium as conventional mineral oil or FR3 natural ester for elevated fire point and eco-compliance. Incorporate specialized features such as K-factor enhancements for harmonic-rich environments, integrated vacuum fault interrupters (VFI), surge arresters, or advanced instrumentation with remote monitoring capabilities.
Further refinements include enclosure enhancements like stainless steel hardware for harsh or coastal conditions, seismic-rated bracing, upgraded corrosion-resistant coatings, or non-standard colors. Add protection schemes such as differential relays, overcurrent devices, or electrostatic shielding. These versatile modifications ensure alignment with IEEE, DOE, CSA, UL, and project-specific codes, enabling deployment in specialized scenarios like data centers, renewable energy tie-ins, industrial facilities, or utility substations, while prioritizing efficiency, personnel safety, and long-term durability customized to your infrastructure demands.
Packing and Shipping
800kVA Three Phase Pad Mounted Transformer
NPC Electric 800kVA three phase pad mounted transformer undergoes meticulous packaging to endure demanding transport stresses, including shocks, vibrations, humidity, and temperature variations. The assembled transformer – encompassing the tank, bushings, cabinetry, and peripherals – is anchored onto a reinforced wooden pallet or skid with structural supports to eliminate shifting. Vulnerable elements like bushings, external gauges, valves, and fittings receive dedicated protective wrapping with impact-absorbent foam, rubber blocks, and secure fastenings to avoid damage from handling or transit forces.
For superior safeguarding, the unit is fully shrouded in heavy-duty moisture-proof poly sheeting and hermetically sealed. It is then placed inside a bespoke export-quality wooden crate with reinforced framing, diagonal bracing, and cushioning layers to absorb dynamic loads. Packaging adheres to ISPM-15 international heat-treatment and fumigation norms, with added desiccant agents and humidity monitoring cards to track conditions and prevent condensation issues. External metal surfaces get a protective anti-corrosion treatment, and lifting points remain unobstructed for efficient crane operations, meeting ANSI/IEEE export guidelines.
Transport is facilitated via established carriers with options for 40ft high-cube sea containers (FCL) for overseas shipments, specialized flatbed trailers for overland/domestic routes, or heavy-haul logistics for large-scale movements. Comprehensive services include real-time shipment tracking, full-value marine/land insurance, and thorough export paperwork (invoices, packing lists, origin certificates, test documentation). Typical delivery timelines span 3-5 weeks for standard stock units and 8-12 weeks for customized builds, with priority expediting possible based on availability.
At the destination, unloading should utilize the integrated lifting lugs with appropriate rigging, followed by prompt inspection for shipping-related issues. The robust packaging ensures the transformer reaches the site in optimal condition, primed for immediate pad mounting and commissioning, while upholding the complete warranty and reducing on-site handling requirements or supplementary expenses.
For superior safeguarding, the unit is fully shrouded in heavy-duty moisture-proof poly sheeting and hermetically sealed. It is then placed inside a bespoke export-quality wooden crate with reinforced framing, diagonal bracing, and cushioning layers to absorb dynamic loads. Packaging adheres to ISPM-15 international heat-treatment and fumigation norms, with added desiccant agents and humidity monitoring cards to track conditions and prevent condensation issues. External metal surfaces get a protective anti-corrosion treatment, and lifting points remain unobstructed for efficient crane operations, meeting ANSI/IEEE export guidelines.
Transport is facilitated via established carriers with options for 40ft high-cube sea containers (FCL) for overseas shipments, specialized flatbed trailers for overland/domestic routes, or heavy-haul logistics for large-scale movements. Comprehensive services include real-time shipment tracking, full-value marine/land insurance, and thorough export paperwork (invoices, packing lists, origin certificates, test documentation). Typical delivery timelines span 3-5 weeks for standard stock units and 8-12 weeks for customized builds, with priority expediting possible based on availability.
At the destination, unloading should utilize the integrated lifting lugs with appropriate rigging, followed by prompt inspection for shipping-related issues. The robust packaging ensures the transformer reaches the site in optimal condition, primed for immediate pad mounting and commissioning, while upholding the complete warranty and reducing on-site handling requirements or supplementary expenses.
32
32 years of industry experience
Manufacturer Test
800kVA Three Phase Pad Mounted Transformer
Progress test
With core-coil installed, tank fabrication integrity is evaluated through weld inspections (ultrasonic/dye penetrant), ensuring no leaks. Enclosure components like doors, latching systems, sills, bushings, and accessories are checked for alignment, functionality, and tamper-proof compliance. Tap changer, gauges, valves, and grounding features receive torque and operational verification. Positive/negative pressure testing confirms tank hermeticity before oil filling. Final pre-test inspections cover overall cleanliness, no contaminants, secure nameplate/ground pads, and basic electrical continuity, preparing the unit for exhaustive Factory Acceptance Testing.
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)
♦ Applied Voltage
♦ Induced Voltage
♦ Lightning Impulse
♦ Insulation Resistance (Rated Voltage)
♦ Temperature Rise
♦ Dielectric Withstand (Hipot)
Transformer Factory Acceptance Test
Impulse (full-wave BIL) testing assesses surge withstand, complemented by partial discharge evaluation (<5 pC limit). Functional assessments confirm tap changer smoothness/position accuracy, pressure relief operation, gauge precision, and accessory performance (valves, sampling). Tank leak test under pressure ensures sealing, with post-fill oil tests for dielectric breakdown, moisture, and DGA. All outcomes are compiled in a certified report with environmental data, affirming the 800kVA pad mounted transformer satisfies contractual and industry requirements before dispatch.
Routine Test - Polarity 1-Ph
Purpose of Testing
The purpose of testing the polarity of a single-phase transformer is to ensure that the primary and secondary windings are correctly oriented, preventing issues like improper phase connection. It also verifies that the transformer operates safely and efficiently in the intended electrical system.
Testing Equipment
Test equipment: Polarity Tester (e.g. Megger, Hioki, etc.)
Voltage source: usually 500 V, 1000 V or customized as needed
Environmental monitoring: Temperature and humidity meter (records ambient temperature and humidity)
Voltage source: usually 500 V, 1000 V or customized as needed
Environmental monitoring: Temperature and humidity meter (records ambient temperature and humidity)
Pre-Test Preparation
Disconnect the device from the power supply and ensure that it is properly grounded and discharged.
Check the connection terminals and wiring to ensure that there is no looseness or contamination.
Test under suitable environmental conditions: relative humidity less than 75% and no rain (recommended temperature: 20-30°C).
Check the connection terminals and wiring to ensure that there is no looseness or contamination.
Test under suitable environmental conditions: relative humidity less than 75% and no rain (recommended temperature: 20-30°C).
Test Progress
Connect the Test Instrument:
Connect the test equipment to the bushing or terminal of the device under test and ensure proper grounding.
Apply Test Voltage:
Select the appropriate test voltage according to the rated voltage of the device. For single-phase systems, the applied voltage should comply with the equipment specifications (such as 220V or 380V, etc.).
Connect the test equipment to the bushing or terminal of the device under test and ensure proper grounding.
Apply Test Voltage:
Select the appropriate test voltage according to the rated voltage of the device. For single-phase systems, the applied voltage should comply with the equipment specifications (such as 220V or 380V, etc.).
Measure and Record
Start the test and record Start the test and record the following parameters:
Phase sequence: Confirm whether the phase sequence of the power supply is correct.
Polarity: Check whether the wiring meets the predetermined polarity (positive and negative terminals are connected correctly).
Voltage: The actual voltage value during the test.following parameters:
Insulation resistance value (MΩ)
Applied voltage
Ambient temperature and humidity during testing
Phase sequence: Confirm whether the phase sequence of the power supply is correct.
Polarity: Check whether the wiring meets the predetermined polarity (positive and negative terminals are connected correctly).
Voltage: The actual voltage value during the test.following parameters:
Insulation resistance value (MΩ)
Applied voltage
Ambient temperature and humidity during testing
Temperature Correction
Measure different wiring points (such as input and output) for comparative analysis to ensure that the electrical polarity is consistent.
Repeat Testing (if necessary)
If necessary, correct the measured parameters to the reference temperature (usually 20°C) to ensure the accuracy of the test results.
Evaluation Criteria (Reference)
Correct polarity: The wiring meets the expected polarity requirements and meets the standard. Reverse polarity: If reverse polarity occurs, it should be corrected immediately and retested. Polarity uncertainty: If there is any uncertainty, further check the power supply and wiring configuration.
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
Optimal for heavy industrial facilities, data centers, healthcare complexes, renewable projects (solar/wind), EV infrastructure, and utility substations. Delivers secure, high-capacity voltage transformation for machinery, critical operations, blockchain setups, and grid support in high-reliability, high-power environments.
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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