Built to Endure, Designed to Perform: The Three Phase Pad Mounted Transformer.
01 General
1.1 Project Description
225 kVA three phase pad mounted transformer was delivered to America in 2025. The rated power of the transformer is 225 kVA with ONAN cooling. The high voltage is 34.5GRDY/19.92 kV with ±2*2.5% tapping range (NLTC), the low voltage is 0.208GrdY/0.12 kV, they formed a vector group of YNyn0.
The green steel cabinet you see on the sidewalk near a shopping center, or nestled beside a new office building, is more than just utility equipment-it’s a Three-Phase Pad-Mounted Transformer, the silent workhorse delivering safe, usable electricity to your community and business.
Engineered for safety, durability, and environmental harmony, our pad-mounted transformers are built to last inside a rugged steel enclosure. This fully sealed, lockable steel housing provides superior protection against weather, physical impact, and unauthorized access, making them ideal for public spaces. The strength of the steel construction ensures the integrity of the internal components, which are cooled and insulated by dielectric fluid. Advanced design and high-quality materials, including the protective steel shell, ensure high efficiency and a long service life with minimal maintenance.
By choosing our pad-mounted transformers, you are investing in a physically robust, safe, and proven solution for your critical power distribution needs.
1.2 Technical Specification
225 kVA pad mounted transformer specifications type and data sheet
| Delivered to | USA |
| Year | 2024 |
| Type | Pad mounted transformer |
| Standard | IEEE C57.12.00 |
| Rated Power | 225 kVA |
| Frequency | 60HZ |
| Phase | 3 |
| Feed | Loop |
| Front | Dead |
| Cooling Type | ONAN |
| Primary Voltage | 34.5GRDY/19.92 kV |
| Secondary Voltage | 0.208GrdY/0.12 kV |
| Winding Material | Aluminum |
| Angular displacement | YNyn0 |
| Impedance | 5% |
| Efficiency | 99% |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5% |
| No Load Loss | 0.395 kW |
| On Load Loss | 3.285 kW |
1.3 Drawings
225 kVA pad mounted transformer diagram drawing and size.
02 Manufacturing
2.1 Core
The core of a three-phase pad-mounted transformer is typically a three-legged design constructed from high-grade, cold-rolled grain-oriented silicon steel laminations. Each leg of the core concentrically supports the primary and secondary windings for one phase. This efficient and compact configuration provides a common magnetic circuit for the three phases, minimizing flux paths, core losses, and no-load current for reliable and economical operation.
2.2 Winding
This transformer’s windings combine an aluminum foil low-voltage (LV) winding with a copper wire high-voltage (HV) winding. The aluminum foil provides a robust, cost-effective LV structure with superior short-circuit strength, while the copper wire allows for precise, layered HV coils with excellent dielectric properties and space efficiency.
2.3 Tank
The tank is a sealed, robust steel enclosure designed for outdoor installation and corrosion resistance. It securely houses the core and coil assembly, filled with dielectric fluid for insulation and cooling. Its tamper-resistant design includes integrated cooling fin to dissipate heat effectively.
2.4 Final Assembly
The final assembly integrates the core and coil, tap changer, and accessories into a robust, sealed steel tank filled with dielectric fluid. This compact, low-profile unit is complete with external components such as tap changer, a pressurized protection system, and pad-mounted compartments for safely housing the HV and LV cables.
03 Testing
The routine tests ensure operational integrity and performance. These include insulation resistance, turns ratio, and polarity verification, followed by AC withstand voltage tests on both the separate source and induced supply. Losses are quantified through no-load and load loss measurements, while impedance calculation and a final seal test confirm electrical efficiency and tank integrity.
04 Packing and Shipping
4.1 Packing
For the three phase pad mounted transformer packaging, first place a layer of tin foil bag on the transformer tray, cover the transformer with the bag, put desiccant inside, then seal the bag leaving an opening. Use a vacuum cleaner to extract gas from the bag and seal the opening with a sealing machine. Next, add corner protectors (made of foam, plastic or cardboard) around the transformer and wrap it with protective film. Finally, package it in an external wooden crate that is sprayed with forklift markings and center of gravity markings.
4.2 Shipping
The transformer is first transported by truck to the port, where it is securely loaded into an ISO container. This container then travels via ocean freight to a U.S. port. This intermodal method ensures seamless, damage-free handling and cost-effective shipping from the manufacturing plant to its final destination in the United States.
05 Site And Summary
As a cornerstone of the modern distribution grid, our Three-Phase Pad-Mounted Transformer is engineered for unwavering reliability and long-term value. It represents not just a product, but a commitment to empowering your community with safe and efficient electricity. We are ready to partner with you to ensure a resilient energy future.
