500 kVA Pad Mount Transformer-13.8/0.48 kV | USA 2025

Exceptional quality, leading technology—Let three-phase pad-mounted transformers provide you with the best power solutions!

01 General

1.1 Project Description

500 kVA three phase pad mounted transformer was delivered to America in 2025. The rated power of the transformer is 500 kVA with ONAN cooling. The primary voltage is 13.8D kV, the secondary voltage is 0.48y/0.277 kV with ±2*2.5% tapping range (NLTC), they formed a vector group of Dyn11.

The Internal Fault Detectors (IFD) system continuously monitors the transformer’s current, voltage, and temperature, enabling it to promptly identify electrical faults and alert maintenance personnel through visual and audible alarms. The transformer’s design prioritizes personnel safety, with all electrical connections rigorously insulated and equipped with safety doors for safer maintenance and inspection. The SCOTECH three-phase pad mounted transformer is widely used in urban power distribution, commercial facilities, industrial production, and residential communities, making it an indispensable part of modern power networks. It is particularly well-suited for integration with underground cable systems, providing reliable power solutions for urban infrastructure.

1.2 Technical Specification

500 KVA pad mounted transformer specifications type and data sheet

1.3 Drawings

500 kVA pad mounted transformer diagram drawing and size.

02 Manufacturing

2.1 Live Front

Live Front is a design where high-voltage terminal blocks are exposed (directly visible and accessible); electrical components using this design allow direct contact (protected by insulating materials like rubber sleeves), offer flexible cable connection (adapting to diverse power access needs), demand high operator skills/concentration (for safe operation with exposed high-voltage parts), and suit specific scenarios (e.g., temporary power supply) requiring frequent wiring or adjustments.

2.2 Radial Feed

Pad mounted transformer’s radial feed (terminal type) is a power supply topology where the transformer acts as the central node, and power is delivered to multiple load units through separate, radiating (star-like) lines (as shown in the diagram: the transformer at the center connects directly to each load via an independent circuit). Its key traits include: simple structure and low cost, but with no redundant power paths-if any single line fails, the corresponding load will lose power (since there’s no backup supply route).

2.3 Tank

The oil tank is constructed from high-strength carbon steel, which offers excellent mechanical properties, high temperature resistance, and corrosion resistance. Transformer and compartments are painted with primer paint. Paint exterior color is ANSI standard #70 gloss gray epoxy finish to withstand industrial environment with sulfur dioxide exposure. The oil tank is equipped with safety valves to relieve excessive internal pressure, preventing rupture or leakage due to overpressure.

2.4 IFD

The IFD (Internal Fault arc Detection) system in pad-mounted transformers is a critical safety feature designed to rapidly detect and mitigate internal arcing faults caused by short circuits. It utilizes integrated pressure and/or light sensors to instantly identify fault conditions, triggering the tripping of upstream breakers or fuses within milliseconds. Simultaneously, built-in pressure relief vents safely direct explosive gases away from personnel and equipment. This integrated protection prevents catastrophic tank ruptures, contains the fault, enhances public safety in populated areas, and minimizes damage to the transformer and the surrounding electrical grid.

03 Testing

Testing of pad-mounted transformers includes three main phases: routine factory tests on each unit (insulation resistance, turns ratio, winding resistance, no-load/loss measurements, and applied voltage tests), type tests for design validation (temperature rise, impulse withstand, and short-circuit capability), and field acceptance tests after installation (insulating fluid analysis, protective device calibration, and functional checks). All tests comply with standards such as IEEE C57.12.00 to ensure electrical performance, mechanical integrity, and long-term operational safety and reliability.

04 Others

4.1 Bayonet Fuse

The bayonet fuse is a current-limiting fuse with a plug-in design, installed on the high-voltage side as a backup protection against internal or severe secondary-side faults. Its bayonet-style contact design allows for safe, manual replacement after de-energization. The fuse provides current-limiting interruption to rapidly cut off high-magnitude fault currents, preventing transformer damage. It typically includes a visual indicator (e.g., a spring-loaded striker pin) for clear fault identification. The fuse rating is coordinated with the transformer’s capacity and system short-circuit level to ensure selective operation with upstream protection, offering a simple and reliable outdoor protection solution.

4.2 No PCB

“No PCB” means the unit contains no polychlorinated biphenyls. PCBs were once common in dielectric and coolant fluids but are now globally banned due to their extreme toxicity, environmental persistence, and bioaccumulation. Modern transformers instead use environmentally safe alternatives such as PCB-free mineral oil, synthetic esters, or silicone-based fluids for insulation and cooling. This designation confirms the product’s compliance with strict environmental and safety regulations (e.g., EPA/TSCA) and reflects a commitment to protecting both human health and the ecosystem throughout the transformer’s lifecycle.

05 Packing and Shipping

06 Site And Summary

In modern power systems, the three-phase pad-mounted transformer stands out as a key solution for power distribution, thanks to its exceptional performance and reliable design. Our pad-mounted transformers utilize advanced technology and high-quality materials, ensuring stable operation in a variety of harsh environments. Whether in urban distribution networks or industrial facilities, you can rely on our products to provide safe and efficient power support. By choosing our three-phase pad mounted transformers, you will gain lasting value and unparalleled service. Let us work together to create a brighter future for power distribution!