Scotech pad-mounted transformers with loop feed deliver safe, reliable power
01 General
1.1 Project Description
This 750kVA three phase pad mounted transformer was delivered to America in 2024. It is made under IEEE Std C57.12.34-2022 and meets the DOE 2016 energy efficiency standard. The efficiency is 99.4%. It has a loop feed and dead-front design for safe and easy use in industrial and commercial areas. The rated power is 750kVA, with a primary voltage of 13.2 kV and a secondary voltage of 0.48 kV. The transformer is UL listed, meeting U.S. safety standards.
The impedance is 5.75%. The no-load loss is 1.05kW. The load loss is 5.4kW. These low losses save energy and improve performance. The tap changer is no-load type (NLTC). It has a ±2×2.5% range to adjust the voltage.
Aluminum windings are light, strong, and good for heat transfer. It keeps the transformer cool and stable under load. The ONAN cooling system uses natural oil and air flow to control temperature.
The tank is made of mild steel and coated with anti-corrosion paint. It is strong and leak-proof. The dead-front structure keeps users safe by covering live parts. The loop feed system allows continuous operation when one side is under maintenance, which improves reliability in power networks.
This transformer is used in Industrial facilities and utility distribution systems. It is also suitable for commercial centers, data facilities, and outdoor substations. It provides stable and efficient power where reliability and safety are important.
1.2 Technical Specification
750kVA three phase pad mounted transformer specification and data sheet
| Delivered to | America |
| Year | 2024 |
| Type | Three phase pad mount transformer |
| Standard | IEEE Std C57.12.34-2022 |
| Rated Power | 750KVA |
| Frequency | 60HZ |
| Feed | Loop |
| Front | Dead |
| Phase | three |
| Cooling Type | ONAN |
| Liquid insulant | Mineral Oil |
| Primary Voltage | 13.2 kV |
| Secondary Voltage | 0.48 kV |
| Vector Group | Dyn1 |
| Winding Material | Aluminum |
| Impedance | 5.75% |
| Efficiency and Losses Standard | DOE 2016 , 99.4% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5% |
| No Load Loss | 1.05 kV |
| On Load Loss | 5.4 kV |
| Accessories | Standard Configuration |
1.3 Drawings
750kVA three phase pad mounted transformer drawing and nameplate
02 Manufacturing
2.1 Core
This Pad Mounted Transformer Loop Feed is engineered in full compliance with DOE 2016 efficiency standards, achieving 99.4% energy efficiency. The core uses high-grade grain-oriented silicon steel (GOES) with step-lap joints to reduce magnetic flux distortion, significantly lowering no-load loss (1.05 kW) and improving overall energy performance and noise control.
2.2 Winding
The 750 kVA pad mounted transformer loop feed is designed using high-purity aluminum conductors optimized for low resistance and reduced load losses (5.4 kW). Reinforced interlayer insulation enhances dielectric strength and short-circuit withstand capability, ensuring stable performance under continuous industrial and utility load conditions.
2.3 Tank
| The Pad Mounted Transformer Loop Feed tank is constructed from high-strength mild steel with fully sealed bolted cover design. Anti-corrosion coating ensures long service life in harsh environments. Structural optimization reduces stray losses and supports stable magnetic balance, improving overall operational efficiency and mechanical durability. |  |
2.4 Integrated Protection
 | Equipped with HV/LV bushings, LBOR switch, bayonet fuse with CLFs, radiators, pressure relief device, liquid level gauge, vacuum pressure gauge, and dial thermometer. These components ensure safe operation, real-time condition monitoring, and enhanced protection, fully supporting DOE-compliant reliable performance. |
2.5 Final assembly
Core and coil assemblies are precisely aligned and vacuum oil-filled to ensure insulation integrity. Comprehensive factory testing includes ratio, resistance, losses, insulation, dielectric, and leak tests. Final inspection confirms nameplate accuracy and wiring compliance, ensuring every Pad Mounted Transformer Loop Feed meets DOE 2016 efficiency and reliability standards. |  |
03 Testing
Testing Standard
| IEEE C57.12.00-2021 | IEEE Standard for General Requirements for Liquid-Immersed Distribution, Power, and Regulating Transformers |
| IEEE Std C57.12.34-2022 | IEEE Standard Requirements for Pad-Mounted, Compartmental-Type, Self- Cooled, Three-Phase Distribution Transformers, 10 MVA and Smaller; High-Voltage, 34.5 kV Nominal System Voltage and Below; Low-Voltage, 15 kV Nominal System Voltage and Below |
| IEEE C57.12.90-2021 | IEEE Standard Test Code for Liquid-Immersed Distribution, Power, and Regulating Transformer |
Routine Test
1. Resistance Measurements
2. Ratio Tests
3. Phase-relation Test
4. No Load Losses and No Load Current
5. Load Losses Impedance Voltage and Efficiency
6. Applied Voltage Test
7. Induced Voltage Withstand Test
8. Leak Testing with Pressure for Liquid Immersed Transformers
9. Insulation Resistance Measurement
10. Oil Dielectric Test
04 Packing and Shipping
05 Site And Summary
The Scotech 750kVA pad mounted transformer loop feed was delivered to America in 2024. Its loop feed and dead-front design provide safety, easy maintenance, and continuous operation.
The transformer uses a three-limb silicon steel core with low loss and low noise. Aluminum windings give strong performance, good heat transfer, and long service life. Standard and additional accessories include bushings, pressure relief valve, tap changer, bayonet fuse with CLFs, 2-position LBOR switch, liquid level gauge, pressure vacuum gauge, dial-type thermometer, and drain and sample valve.
The transformer is vacuum-filled with mineral oil and passes routine tests for resistance, ratio, phase relation, losses, voltage withstand, insulation, leak, and oil dielectric performance. Scotech transformers deliver reliable, energy-efficient, and cost-effective power for modern 3-phase distribution networks.
