2500 kVA Pad Mount Transformer-12.47/0.48 kV | USA 2025

Engineered for Safety, Built for Performance – Trust Our Pad-Mounted Transformers!

01 General

1.1 Project Description

2500 kVA three phase pad mounted transformer was delivered to America in 2025. The rated power of the transformer is 2500 kVA with ONAN cooling. The primary voltage is 12.47GrdY/7.2 kV with ±2*2.5% tapping range (NLTC), the secondary voltage is 0.48Y/0.277 kV, they formed a vector group of YNyn0.

Our Pad-Mounted Transformer is engineered for superior performance, reliability, and safety in utility and industrial power distribution. Designed with an Internal Fault Detection (IFD) system, it ensures early warning of potential issues, minimizing downtime. The 4-position load break switch allows for flexible operation and safe isolation, while the de-energized tap changer (DETC) enables precise voltage regulation without interrupting service.

Built to withstand harsh conditions, this transformer features seismic anchor provisions for enhanced earthquake resistance. Critical monitoring is simplified with a top oil thermometer, oil level gauge, and vacuum pressure gauge for real-time diagnostics. Safety is further reinforced with a pressure relief device, bayonet fuses, and ELSP (Expulsion) fuses, ensuring overload and fault protection.

Ideal for underground distribution networks, this robust and maintenance-friendly transformer delivers efficient, long-lasting power in a compact, secure enclosure.

1.2 Technical Specification

2500 kVA pad mounted transformer specifications type and data sheet

1.3 Drawings

2500 kVA pad mounted transformer diagram drawing and size.

02 Manufacturing

2.1 Bushing Supports

The more ports a low-voltage bushing has, the longer its matching terminal lug grows. When these lugs (with multiple ports) connect to multiple heavy cables, or when lug extensions are used, low-voltage bushing supports are needed. Too many heavy cables exert downward pressure on unsupported bushings, compressing the bottom of the bushing gasket (between the bushing and tank wall) over time. This can cause transformer oil to leak from the gasket’s top. Bushing supports add upward tension to the bushings, counteracting the cables’ downward pull. This eases strain on the bushing assembly, avoiding gasket compression and leaks.

2.2 Bayonet Fuse

Bayonet fuses are industry-standard expulsion fuses, widely utilized in padmount transformers and power distribution systems. Featuring a thin fusible element that melts under overcurrent or high temperatures, they trigger an internal arc when activated-this arc interacts with the fuse housing’s special lining to generate gas, rapidly extinguishing the arc and cutting off current flow. Common types include current sensing, dual sensing, dual element, and high-amp fuse links. These fuses protect transformers from common hazards like overheating, overloading, secondary faults, and low-level short circuits. Once the issue is resolved by technicians, the fuse can be replaced to re-energize the transformer.

2.3 Tank

Tank is constructed from welded stainless steel, offering excellent corrosion resistance and mechanical strength for diverse outdoor applications. Equipped with high-efficiency cooling fins, the tank significantly enhances heat dissipation capacity by increasing the cooling surface area, ensuring stable long-term operation. Its fully sealed design contains insulating oil and incorporates pressure relief devices, effectively preventing external contamination while accommodating internal pressure fluctuations caused by oil temperature variations.

2.4 IFD

The IFD (Insulation Fault Detection) system in a pad-mounted transformer is an integrated online monitoring device that continuously analyzes dissolved gases-primarily hydrogen-in the insulating oil. By detecting early traces of gas produced by incipient insulation faults, such as partial discharge or overheating, it provides advanced warning long before a serious failure occurs. This enables proactive maintenance, enhances operational safety, and significantly improves the reliability and service life of the transformer.

03 Testing

Insulation Resistance Test:

• Test the insulation resistance of the transformer to ensure that all components (such as the insulation between windings and the ground, and between windings) have sufficient insulation capability to prevent current leakage or short circuits.
• The insulation resistance test is usually conducted using an ohmmeter, with the measurement range typically ranging from several hundred megohms to several thousand megohms.

04 Packing and Shipping

Constructed from welded stainless steel for superior corrosion resistance and mechanical strength, this tank is engineered to perform reliably in diverse outdoor settings. Its high-efficiency cooling fins significantly augment thermal management by expanding the effective cooling surface area, thereby ensuring sustained operational stability over extended periods. The hermetically sealed design, filled with dielectric oil and equipped with integrated pressure relief mechanisms, effectively prevents ingress of external contaminants while accommodating internal pressure variations induced by thermal expansion.

05 Site And Summary

As a reliable cornerstone of distribution systems, our pad-mounted transformers combine innovative design with rigorous craftsmanship, delivering unmatched efficiency and durability for diverse outdoor applications. From customized solutions to global delivery, we are committed to providing safe and intelligent power solutions, empowering a more resilient grid future.