Three Phase Pad Mounted Transformer
GE Transformer manufactures premium three phase pad mounted transformers designed to meet the rigorous demands of commercial, industrial, and renewable energy sectors. Built with tamper-resistant enclosures and advanced insulation technologies, our transformers guarantee secure and uninterrupted power step-down performance, even in the harshest outdoor environments. Whether you need a standard configuration or a highly customized unit, we deliver solutions that align perfectly with your project specifications.
- Power Ratings: 45 kVA up to 5000 kVA.
- Voltage Classes: Up to 34.5 kV (custom multi-voltage available).
- Design Options: Loop Feed or Radial Feed, Dead Front or Live Front.
- Certifications: Designed, manufactured, and tested to meet or exceed IEEE C57.12.34, NEMA, and ANSI requirements.
- Eco-Friendly Options: Available with biodegradable FR3 fluid for enhanced fire safety and environmental compliance.
Three Phase Pad Mounted Transformer
Three phase pad mounted transformer type
Primary Feeding Method:
Loop Feed (Dual-Power Supply)
Designed for grid redundancy, the loop feed transformer features six (6) high-voltage bushings for incoming and outgoing primary cables. If a fault occurs, it seamlessly draws power from the alternative side of the utility loop. This minimizes downtime, making it essential for critical infrastructure, data centers, and heavy industrial facilities.
Radial Feed (Single-Circuit Supply)
Featuring three (3) high-voltage bushings, the radial feed design offers a simpler, budget-friendly, single-source connection. Because it relies on a single circuit, any upstream fault or maintenance will cause a temporary power outage. It is best suited for isolated industrial loads or end-of-line projects where maintenance shutdowns are acceptable.
Safety Configuration:
Dead-Front Design (North American Standard)
Featuring fully shielded, watertight high-voltage terminations, this design ensures zero exposed live parts when the cabinet is open. Technicians can safely operate loadbreak elbows without de-energizing the entire system. Its maximum safety profile makes it ideal for public utilities, commercial centers, and high-traffic residential areas.
Live-Front Design
This configuration utilizes exposed high-voltage porcelain or epoxy bushings, allowing for straightforward visual inspections. However, it strictly requires the transformer to be completely de-energized and grounded before any maintenance. Due to exposed live parts, it is restricted to secure industrial substations or remote renewable energy sites accessible only to qualified personnel.
Comprehensive Components & Optional Accessories
Primary (High Voltage) Components
High-Voltage Bushings: Robust construction for secure primary connections.
Switching Options: Available with loadbreak switches or no-load tap changers.
Separable Insulated Connectors: High-quality elbow connectors for dead-front safety.
Overvoltage Protection: Under-oil or elbow-mounted surge arresters.
Dual-Fusing Protection: Field-replaceable Bay-O-Net expulsion fuses paired with current-limiting backup fuses (ELSP) for high-energy fault interruption.
HV Compartment: Spacious, compartmentalized design with secure and easily accessible cable terminations.
Secondary (Low Voltage) Components
Low-Voltage Bushings: High-capacity spade terminals or customized bushing configurations.
Connection Terminals: Heavy-duty busbars and secure cable connection terminals.
Circuit Protection: Optional low-voltage circuit breakers.
Metering Integration: Built-in Current Transformers (CTs) for accurate metering and system protection.
Transformer Tank & Regulation
Tap Changer: Externally operable Off-Circuit Tap Changer (OCTC) for precise voltage adjustment.
Hermetically Sealed Tank: Leak-proof design filled with premium insulating fluid (available in standard mineral oil or highly bio-degradable FR3 fluid).
Pressure Relief Device (PRD): Automatic pressure relief for internal fault protection and safety.
Valves & Maintenance: Easily accessible oil filling and drain valves with sampling provisions.
Protection & Monitoring
Precision Sensors: Integrated temperature sensors (RTD/PTC) for accurate thermal tracking.
Gauges: Dial thermometers, pressure/vacuum gauges, and liquid level indicators.
Alarm Contacts: Gauges can be equipped with auxiliary contacts to signal abnormal conditions.
Smart Grid Ready: Optional interfaces for remote monitoring and SCADA system integration.
Enclosure & Safety Features
Secure Enclosure: Tamper-resistant, lockable steel enclosure designed to prevent unauthorized access.
Compartmentalized Layout: Physically separated HV, LV, and main transformer tank sections for operational safety.
Grounding: Heavy-duty grounding pads in both HV and LV compartments for safe earthing.
Extreme Environment Protection: Premium corrosion-resistant coating for outdoor durability. For coastal or marine environments, 316-grade stainless steel construction and C5-M class marine-grade paint finishes are available.
Thermal Management: Optimized ventilation design for efficient heat dissipation under full load.
Additional Features
Stainless Steel Nameplate: Laser-engraved with detailed ratings, connection diagrams, and specific standard compliance.
Handling & Installation: Heavy-duty lifting lugs and a rugged skid base for stable mounting and secure transportation.
Cable Management: Adjustable cable supports and robust clamps to reduce terminal stress.
Three Phase Pad Mounted Transformer Parameters
| Item | Three-Phase Pad-Mounted |
| Transformer Type | Loop feed & Radial feed |
| Capacity Range (kVA) | 45 kVA – 5000 kVA |
| Primary Voltage (HV) | 34.5-19.92 / 13.8-7.957 / 13.2-7.62 / 12.47-7.2 kV or others |
| Rated Frequency | 50 Hz / 60 Hz |
| Winding Material | Copper / Aluminum |
| Winding Connection / Vector Group | Dyn11, Ynd11, Yyn0 (Or customized) |
| Insulating Fluid | Mineral Oil / FR3 |
| Cooling Type | ONAN / ONAF, KNAN / KNAF |
| Tap Changer | ±2 x 2.5% Off-Circuit Tap Changer (OCTC) |
| Impedance | 4.0% – 6.0% (Or customized) |
| Average Winding Temp. Rise | 55°C (Based on 40°C Max Ambient) |
| Top-Oil Temp. Rise | 65°C (Based on 40°C Max Ambient) |
| Sound Level | ≤ 55 dB (measured at 1 meter) |
| Enclosure Material | Galvanized steel, 304/316L Stainless Steel options |
| Altitude | ≤1,000m or Customized |
| Ambient Temperature Range | -40°C to +50°C |
| Standards Compliance | ANSI C57.12.25, IEEE C57.12.25, IEC 60076 |
| Warranty | Typically one year, depending on the client’s specific needs |
| Delivery Time | Generally, it is 20-30 days. It is according to the quantity. |
| Min. order quantity | ≧ 1 set |
Three phase pad mounted transformer Drawing
Factory Testing & Quality Control (FAT & QC)
1. Routine Tests (100% Performed on All Units)
- Voltage Ratio & Phase Relation: Verifies accurate turns ratio, proper polarity, and vector group alignment across all tap positions.
- Insulation Resistance Test (Megger): Assesses the integrity of insulation between windings and from windings to the ground.
- Dielectric Tests (Applied & Induced Voltage): Subjects the transformer to high-voltage stresses to ensure the insulation system can withstand operational transients.
- No-Load Loss & Excitation Current: Measures core losses and magnetizing current at rated voltage to verify energy efficiency limits.
- Load Loss & Impedance Voltage: Determines winding copper/aluminum losses and impedance to ensure optimal voltage regulation and short-circuit capability.
- Transformer Tank Leak Test: The completely assembled tank undergoes a pressurized oil leak test for a minimum of 24 hours to guarantee absolute hermetic sealing.
2. Type & Special Tests (Available Upon Request)
To further validate specialized designs or extreme application requirements, we offer advanced type testing:
- Temperature Rise Test: Confirms the cooling system (ONAN/KNAN) maintains the transformer within specified limits (55°C/65°C) under full load.
- Lightning Impulse Test: Simulates high-voltage lightning surges to verify the impulse insulation strength of the windings.
- Audible Sound Level Test: Measures operational noise compliance with NEMA TR-1 standards for residential or commercial installations.
3. Comprehensive Quality Assurance & Traceability
- Material Inspection: 100% inspection of critical raw materials including high-conductivity copper/aluminum windings and premium silicon steel cores.
- In-Process QC: Strict inspection gates during winding, core stacking, active part assembly, and vacuum oil-filling stages.
- FAT Documentation: A comprehensive, officially signed test report detailing all actual measured parameters is provided with every shipment for your engineering archives.
- Secure Packaging: Export-grade, sea-worthy packaging featuring robust base framing and secure tie-downs compliant with international shipping standards.
Three phase pad mounted transformer Applications
Renewable Energy (Solar & Wind)
The Challenge: Intermittent power generation and strict environmental regulations.
Our Solution: Solar-dedicated step-up transformers integrated with electrostatic shields and FR3™ bio-degradable fluid. Designed to handle inverter harmonics and ensure seamless grid connection with maximum fire safety.
Industrial Manufacturing
The Challenge: Heavy, continuous electrical loads and the need for absolute operational uptime.
Our Solution: Loop-feed configurations providing dual-power supply redundancy. Built with heavy-duty internal components to handle severe load fluctuations and prevent costly facility downtime.
Coastal & Marine Infrastructure
The Challenge: Rapid equipment degradation due to high humidity, salt fog, and extreme weather.
Our Solution: Specialized units featuring 316-grade stainless steel enclosures and C5-M class marine-grade anti-corrosion coatings. Perfectly suited for port facilities, coastal desalination plants, and island grid projects.
Commercial & Public Facilities
The Challenge: Strict safety codes for areas with high pedestrian traffic (schools, hospitals, shopping centers).
Our Solution: Dead-front safety designs with fully insulated, watertight terminations and tamper-resistant IEEE C57.12.28 compliant enclosures. Ensuring zero exposed live parts to guarantee public safety.
Data Centers & Crypto Mining
The Challenge: 24/7 continuous high-density loads resulting in extreme thermal stress.
Our Solution: High-efficiency core designs with optimized ONAN/KNAN cooling layouts. Engineered for superior thermal management and reduced no-load losses, maximizing profitability for energy-intensive operations.
Mining & Heavy Resources
The Challenge: Remote, harsh environments requiring rugged, low-maintenance equipment.
Our Solution: Structurally reinforced tanks with heavy-duty skid bases for secure transport to remote sites. Equipped with advanced monitoring gauges and surge arresters to protect against unpredictable utility spikes.
Packaging and Shipping
Why Choose GE Transformer
Quality Control: Quality is a core value of GE Transformer. We conduct Factory Acceptance Testing (FAT), type testing, and third-party inspections to ensure superior quality. We strictly adhere to the ISO 9001 quality management system, committed to providing our customers with the highest quality products.
Professional Team: Our team comprises highly skilled professionals dedicated to responding quickly to customer needs. All GE Transformer team members receive systematic training and continuously improve their capabilities through rigorous quality standards and practices. Our commitment to customer service, product innovation, engineering excellence, and social and environmental responsibility makes us a trusted partner in the global power industry.
Certifications
- ISO9001：2015
- CE Certifications:
- UL Certifications:
- CSA Certification:
- CNAS Certification:
Competitive Market Pricing:Leveraging years of industry experience, GE Transformer integrates high-quality resources across R&D, production, procurement, transportation, and service, achieving effective cost control.
Fast Delivery: Strong production capacity, multiple freight partners, and a professional pre-sales and after-sales team, adhering to the “customer first” philosophy, provide customers with fast delivery and usage services.
FAQ
Q1: What international standards do your pad-mounted transformers comply with?
A: Our three-phase pad-mounted transformers are engineered, manufactured, and tested in strict accordance with IEEE C57.12.34, ANSI, and relevant IEC standards. We ensure all electrical clearances, testing protocols (such as IEEE C57.12.90), and safety features meet the highest global utility and industrial requirements.
Q2: How do I choose between a Loop Feed and a Radial Feed configuration?
A: The choice depends on your grid redundancy requirements. A Radial Feed unit has three high-voltage bushings and connects to a single power source, making it cost-effective for end-of-line projects. A Loop Feed unit features six bushings and connects to two power sources in a circuit loop. If one line fails, the transformer can draw power from the other, drastically minimizing downtime for critical facilities like hospitals or data centers.
Q3: Can these transformers be deployed in high-salinity or harsh marine environments?
A: Yes. For coastal regions or heavy industrial sites, we highly recommend upgrading to a 304 or 316-grade stainless steel enclosure. Furthermore, we apply a C5-M class marine-grade anti-corrosion coating system to ensure long-term durability and prevent structural degradation from salt fog and extreme humidity.
Q4: Do you offer environmentally friendly or fire-resistant insulating fluids?
A: Absolutely. While Type II mineral oil is standard, we frequently utilize FR3™ natural ester fluid for projects requiring enhanced safety and environmental compliance. FR3 is a rapidly biodegradable vegetable oil with a high fire point (over 300°C), making it the premier choice for renewable energy sites and densely populated commercial areas.
Q5: Are your pad-mounted units suitable for facilities with high non-linear loads?
A: Yes. For industrial plants, data centers, or renewable inverter systems dealing with severe harmonic distortion, we can integrate specialized Harmonic Mitigating Transformer designs into our pad-mounted units. These heavy-duty core and winding configurations are built to handle excess heat generated by harmonics without degrading the transformer’s lifespan.
Q6: Is it possible to manufacture a transformer with dual high-voltage ratings?
A: Yes, we frequently build dual-voltage pad-mounted transformers (e.g., 12.47 kV × 24.94 kV) equipped with an externally operable voltage selector switch. This allows utilities and private facilities to adapt to future grid upgrades without needing to replace the entire transformer unit.
Q7: What is your typical production lead time? How do you ensure safe transportation for international sea freight?
A: Our standard production lead time is typically 3 to 4 weeks, depending on the order quantity, kVA capacity, and the complexity of any custom specifications. For international logistics, we strictly adhere to heavy-duty sea freight packaging standards. The entire unit is wrapped in multiple layers of moisture-proof material and rust-proof film, and industrial-grade desiccants are included to completely eliminate the risk of salt fog corrosion. We support flexible trade terms (including FOB, CIF, etc.) and provide a full set of shipping documents (such as certified FAT reports, packing lists, etc.) to ensure smooth customs clearance at the port of destination.