From source to endpoint, pad-mounted transformer empowers every kilowatt-hour.
01 General
1.1 Project Description
112.5 kVA pad mounted transformer was delivered to China in 2024. The rated power of the transformer is 112.5 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 Three-Phase Pad-Mounted Transformer is a widely used power distribution device in distribution systems, primarily providing power for residential areas, commercial districts, industrial parks, and other locations. The three-phase pad-mounted transformer receives electrical energy through its high-voltage side and steps down the high voltage to a low voltage for supply to electrical equipment. The high-voltage side is typically connected through a ring network or terminal feed, while the low-voltage side delivers power to the load. Internal load switches and fuses provide protection to ensure the safe operation of the equipment. Fuses and cable terminals are integrated into the same cable compartment, with optimized spatial design ensuring easy access for operations and maintenance. The conductive structure connecting the fuse and cable terminal is precisely designed, using high-conductivity materials (e.g., silver-plated copper) and precision contact technology to minimize contact resistance and ensure excellent electrical performance.
1.2 Technical Specification
112.5 kVA pad mounted transformer specifications type and data sheet
| Delivered to | China |
| Year | 2024 |
| Type | Pad mounted transformer |
| Standard | ANSI Standard |
| Rated Power | 112.5KVA |
| Frequency | 60HZ |
| 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 | 3.5%(±7.5%) |
| Tap Changer | NLTC |
| Tapping Range | ±2*2.5% |
| No Load Loss | 0.355KW |
| On Load Loss | 1.450KW |
| Accessories | Standard Configuration |
1.3 Drawings
112.5 kVA pad mounted transformer diagram drawing and size.
02 Manufacturing
2.1 Core
| The core consists of three vertical legs (columns), Each leg carries two sets of windings (high-voltage winding and low-voltage winding), corresponding to the three-phase currents (phases A, B, and C). The three legs are connected by horizontal yokes, forming a closed magnetic path. The three-legged structure ensures symmetrical magnetic circuits, reducing the likelihood of magnetic imbalances. The three-legged structure ensures symmetrical magnetic circuits, reducing the likelihood of magnetic imbalances. |  |
2.2 Winding
 | High-voltage wire winding can adjust the number of turns and spacing through layered designs, meeting the requirements of various high voltage levels while enhancing insulation performance and safety. By employing reasonable layering and segmenting techniques, wire winding can optimize the electric field distribution effectively, preventing excessive local electric fields that may lead to insulation failure. In wire winding, cooling channels can be incorporated into the structure to improve heat dissipation, ensuring the long-term stable operation of high-voltage windings. The mechanical strength of wire winding depends on the conductor material and winding process, allowing for the design of suitable tensile strength and deformation resistance as needed. |
2.3 Tank
| The box design fully considers the requirements of waterproof, safety and easy operation. The high and low voltage chamber protective doors are mechanically interlocked, and only when the low pressure protective door is opened, the high pressure protective door can be opened to ensure the safety of operation and maintenance personnel. The box is made of high quality carbon steel plate, which is made by precision machining of each process. After strict surface treatment of the inner and outer surfaces of the box, the advanced electrostatic powder spraying process is used for three times powder treatment, and the paint layer is strong, wear-resistant and waterproof, and resistant to ultraviolet radiation. |  |
2.4 Final Assembly
 | Enclosure Assembly: Install the base, cabinet, and top cover; separate compartments and ensure waterproofing. Core and Windings: Place the iron core, assemble windings, and perform insulation and fastening. Cooling System: Install radiators, fill oil, and remove air. Wiring: Connect high-voltage and low-voltage terminals. Protective Devices: Install switches, fuses, lightning arresters, and monitoring equipment. Sealing and Coating: Seal the enclosure, apply anti-corrosion coating, and ground. |
03 Testing
Routine Tests:
- Measure winding resistance.
- Check transformer voltage ratio and connection group.
- Measure no-load loss and current.
- Measure load loss and impedance voltage.
Withstand Voltage Tests:
- Power frequency withstand voltage test (to test insulation performance of the winding).
- Induced overvoltage test (to check insulation performance of windings and core).
Special Tests (if required):
- Partial discharge test (to detect insulation defects).
- Temperature rise test (to verify cooling system performance).
04 Packing and Shipping
05 Site And Summary
In summary, the 112.5 kva pad mounted transformer combines high efficiency, reliability, and safety in a compact and durable design. With its advanced insulation, superior cooling performance, and robust protective features, it is an ideal solution for urban power distribution, industrial applications, and renewable energy systems. Tailored to meet diverse customer needs, this transformer ensures stable operation, minimal maintenance, and long service life, making it a trusted choice for modern energy infrastructure.
