Perfect blend of beauty and practicality-The new standard for urban power supply!
01 General
1.1 Project Background
This 750 kVA pad-mounted transformer was delivered to Jamaica in 2024. Rated at 750 kVA, it steps down from 34.5D kV on the primary side to 0.48GrdY/0.277 kV on the secondary, with a Dyn1 connection group. Pad-mounted transformers like this one are everywhere-power plants, high-rise buildings, factories, mines, petrochemical plants, transportation hubs-you name it. Inside, the high-voltage load switch and fuse sit safely in the transformer oil. The tank itself is fully sealed, and it comes with all the usual monitors: oil temperature gauge, oil level gauge, pressure gauge, pressure release valve, oil release valve-everything to keep track of the transformer’s operation. It’s versatile too, available in ring network, terminal, or dual power supply setups.
1.2 Technical Highlights
The Dyn1 vector group makes it perfect for urban and industrial ring networks-reliable and predictable.
It uses ONAN natural oil circulation cooling, and the oil tank is completely sealed, so it’s safe and low-maintenance.
The loadbreak switch and high-voltage fuse are immersed in oil-safe operation even under load.
On top of that, the transformer features an NLTC with ±2×2.5% tap range, so voltage regulation is smooth, stable, and easy to adjust without interrupting service.
1.3 Product Advantages
Compact design-fits neatly in urban corners, factories, and even tight mine sites.
Aluminum windings make it lighter and easier to transport and install, without compromising performance.
The full metal enclosure is tough-resistant to moisture, dust, and tampering.
Accessories are all included-oil level gauge, thermometer, pressure gauge, relief valves-so monitoring is straightforward,
everything you need to see the transformer’s status at a glance. Maintenance is simple, operation is safe, and the overall footprint is small but mighty.
1.4 Technical Specification
750 kVA transformer specifications type and data sheet
| Delivered to | Panama |
| Year | 2024 |
| Type | Pad mounted transformer |
| Standard | IEEE C57.12.34 |
| Rated Power | 750KVA |
| Frequency | 60HZ |
| Phase | 3 |
| Feed | Loop |
| Front | Dead |
| Cooling Type | ONAN |
| Primary Voltage | 34.5D KV |
| Secondary Voltage | 0.48/0.277 KV |
| Winding Material | Aluminum |
| Angular displacement | Dyn1 |
| Impedance | 5.75±7.5% |
| Efficiency | 99.53% |
| Tap Changer | NLTC |
| Liquid insulant | Mineral oil |
| Tapping Range | ±2*2.5% |
| No Load Loss | ≤0.91KW |
| On Load Loss | ≤6.05KW |
| Accessories | Standard Configuration |
1.5 Drawings
750 kVA pad mounted transformer diagram drawing and size.
02 Manufacturing
2.1 Core
| Three-phase three-column core transformer is a common transformer structure in power system. It adopts three independent cylindrical core, corresponding to three phase current respectively. This design helps to optimize the distribution of magnetic flux and improve the efficiency of the transformer. Each column is fitted with windings at the top, which can usually be connected in a star or triangle shape to suit different power needs. In manufacturing, the core is made of laminated silicon steel to reduce eddy and hysteresis losses, thereby improving overall energy efficiency. The three-column design can not only effectively reduce the iron loss, but also improve the heat dissipation performance and enhance the stability of the transformer under high load state. |  |
2.2 Winding
 | Low-voltage foil windings utilize wide conductive strips, which help minimize the winding’s inductance and resistance, thereby reducing power loss during current transmission. Furthermore, the layered foil structure promotes uniform current distribution, mitigating localized heating and enhancing overall efficiency. High-voltage wire windings employ finely wound coils designed to withstand elevated voltage levels and provide superior insulation strength. With the high-voltage winding enclosed by the low-voltage foil, this configuration improves electrical isolation, minimizes interference between voltage sections, and ensures safe and stable transformer operation under high-load conditions. |
2.3 Tank
| The transformer tank is an important part of the transformer, which is mainly used to store and protect the insulating oil to ensure the normal operation of the transformer. Its main functions include insulation, cooling and protection against equipment damage due to overheating or internal failure. The tank is usually made of steel and has good sealing and mechanical strength to withstand internal and external pressure changes and environmental impacts. The insulating oil filled in the transformer tank can not only effectively isolate the current and reduce the risk of electrical breakdown, but also has excellent thermal conductivity, helping to dissipate heat and keep the working temperature of the transformer within a safe range. In addition, tanks are often designed with heat sinks or cooling systems to enhance heat exchange efficiency, especially under high load operating conditions. The surface of the tank is usually equipped with an oil level gauge to monitor the status of the oil and the change of the oil level. At the same time, the tank may be equipped with additional devices such as safety valves and breathing apparatus to prevent safety accidents caused by excessive pressure or oil temperature. |  |
2.4 Final Assembly
 | During transformer assembly, the core and windings are first integrated into a solid unit before being placed into the oil tank. The tank is then filled with insulating oil for effective cooling and insulation, followed by hermetic sealing to prevent leaks. A protective steel enclosure is installed to ensure structural integrity, and terminal blocks are finally mounted to enable secure cable connections. |
03 Pad Mounted Utility Transformer Parts
04 Testing
05 Packing and Shipping
5.1 Packing
| The three-phase pad-mounted transformer is packaged within a reinforced steel enclosure with integrated lifting points and forklift channels. Critical components are protected using shock-absorbing covers, while internal bracing minimizes movement during transit. The unit features weather-resistant seals and desiccant units to maintain internal dryness. External identification plates and handling markings provide clear operational guidance. All packaging meets international standards for heavy electrical equipment transportation. |  |
5.2 Shipping
 | The transport of a three-phase pad-mounted transformer is a specialized operation focused on moving a heavy, enclosed unit from manufacturer to site. It requires a pre-approved route survey to manage obstacles, a robust trailer for secure immobilization using blocking and chains, and strict adherence to oversized load regulations. The goal is a damage-free delivery, ensuring the transformer arrives ready for installation on its concrete pad. |
06 Site And Summary
Whether in the construction of urban electrical infrastructure or in the energy supply for industrial parks, the three phase pad mounted transformer demonstrates exceptional flexibility and reliability. With its outstanding performance and durable design, it not only meets diverse electrical needs but also operates steadily in various environmental conditions. We are committed to prioritizing innovation and quality, providing you with the best power solutions. Choose our three phase pad mounted transformer, and let us together move towards a smarter and more sustainable energy future! Thank you for your trust and support!
