Cost-effective and environmentally friendly, leading the way in power transformation — the best choice for three-phase pad-mounted transformers!
01 General
1.1 Project Description
225 kVA three phase pad mounted transformer was delivered to China in 2024. The rated power of the transformer is 225 kVA with ONAN cooling. The primary voltage is 34.5GrdY/19.92kV with ±2*2.5% tapping range (NLTC), the secondary voltage is 0.12/0.208kV, they formed a vector group of YNyn0.
The protection system features a dual-fuse design, with a plug-in fuse (BAY-o-net) that provides dual sensitivity to temperature and current, specifically designed to protect against short-circuit faults on the secondary side of the transformer. Additionally, the backup current-limiting protection fuse (ELSP) effectively prevents incidents caused by internal faults within the transformer, ensuring the safe operation of the high-voltage side and providing extra protection.
Three phase pad mounted transformer are widely used in residential areas, commercial centers, and industrial zones, serving as a crucial component of urban distribution networks. Deep into the load center, ring network and two-way power supply, one installation can achieve power supply.
1.2 Technical Specification
225 KVA transformer specifications type and data sheet
| Delivered to | China |
| Year | 2024 |
| Type | Pad mounted transformer |
| Standard | ANSI Standard |
| Rated Power | 225 kVA |
| Frequency | 60 HZ |
| Phase | 3 |
| Feed | Loop |
| Front | Dead |
| Cooling Type | ONAN |
| Primary Voltage | 34.5GrdY/19.92 kV |
| Secondary Voltage | 0.12/0.208 kV |
| Winding Material | Aluminum |
| Angular displacement | YNyn0 |
| Impedance | 5%(±7.5%) |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5% |
| No Load Loss | 0.395KW |
| On Load Loss | 3.285KW |
| Accessories | Standard Configuration |
1.3 Drawings
225 kVA pad mounted transformer diagram drawing and size.
02 Manufacturing
2.1 Core
| The three-phase five-column core comprises five columns, where three columns are used to support the phase windings, and the remaining two columns form a return path that supports the closure of the electromagnetic field. This design helps balance the magnetic flux and reduce energy loss. Compared to traditional core structures, the five-column core exhibits superior magnetic flux utilization, thermal management, and electromagnetic performance, contributing to the miniaturization and performance enhancement of devices. |  |
2.2 Winding
 | In three-phase pad-mounted transformers, the winding arrangement enables phase balancing. The windings utilize high-quality insulation materials to ensure safety and reliability under high voltage operation. These materials possess good heat resistance and moisture resistance, making them suitable for outdoor environments. The winding design is typically compact, aimed at space-saving and enhancing the overall stability of the structure. This design allows for higher power density and reduces the size of the transformer. |
2.3 Tank
| Fuel tank bolted structure (bolt structure), the welding of the fuel tank is solid and reliable, no burrs and leakage phenomenon, no welding penetration, cracks, pores, welding slag, welding holes, spatter, rust and oil. The internal and external surfaces of the box and the cabinet are clean, smooth, beautiful and smooth; No rust, coating off or bump damage phenomenon, the color brightness of the coating layer is firm and uniform, no color difference. |  |
2.4 Final Assembly
 | Cable Connections: According to the electrical schematics, connect the high-voltage and low-voltage cables, ensuring the connections are secure. Internal Component Installation: Install internal components such as windings, insulation materials, and cooling media inside the transformer housing. Sealing and Inspection: After assembly, carry out sealing procedures to ensure there are no oil leaks or air-tight issues, and inspect all connection points. |
03 Testing
Insulation Resistance Testing: Measuring the insulation resistance between the windings and ground, as well as between the windings themselves.
DC Hi-Pot Testing: Applying DC high voltage to check the insulation level.
AC Hi-Pot Testing: Conducting withstand tests on the high-voltage and low-voltage sides.
Load Testing: Simulating actual load conditions to assess load capacity and temperature rise.
Turns Ratio Testing: Measuring the transformer’s turns ratio to ensure it meets design specifications.
Sound and Vibration Testing: Monitoring running sound and vibration to assess mechanical condition.
04 Packing and Shipping
05 Site And Summary
In conclusion, our three-phase pad-mounted transformers are designed to meet the highest standards of reliability, efficiency, and safety for various applications. With robust construction, advanced insulation, and superior cooling techniques, these transformers are built to withstand demanding environments while delivering consistent performance. Their compact, pad-mounted design allows for easy installation and minimal footprint, making them ideal for urban and industrial settings. Choose our three-phase pad-mounted transformers for your power distribution needs and experience the perfect blend of innovation and durability, ensuring a reliable power supply for years to come.
