3000 kVA Residential Transformer Box-23.9/11.95*13.8 kV | Jamaica 2025

Three-Phase Synergy, Leading the Future of Power—Reliable Supply Begins with Pad Mounted Transformer!

01 General

1.1 Project Background

A 3000 kVA pad mounted transformer was delivered to America in 2025. The rated power of the residential transformer box is 3000 kVA with ONAN cooling. The primary voltage is 23.9GrdY/13.8 kV with ±2*2.5% tapping range (NLTC), the secondary voltage is 11.95GrdY/6.9*13.8D kV, they formed a vector group of YNyn0/YNd11.

Three-phase pad-mounted transformers are usually designed to be compact to fit into the limited space in urban or commercial areas. The transformer, switching equipment, and other components are enclosed within a robust metal housing, allowing for direct installation on the ground. The design offers good environmental adaptability, allowing for use in diverse climatic and geographical conditions, including high humidity and high altitude. Compared to traditional transformers, pad-mounted transformers are easier to install, and routine maintenance and inspections are relatively straightforward, making it easy to replace damaged components quickly. They usually employ oil-immersed cooling, where natural circulation of transformer oil achieves heat dissipation. Pad-mounted transformers are manufactured with power ratings ranging from approximately 15 kVA to 5000 kVA. They often feature integrated fuses and switches for enhanced safety and functionality. The primary power cables can be connected using elbow connectors, which are operable while the transformer is energised using a hot stick. This setup provides flexibility in repair and maintenance, allowing for convenient and efficient service operations.

1.2 Service Conditions

The equipment will be installed outdoors in a tropical coastal environment with severe lightning activity, high humidity, and occasional hurricanes. The ambient atmosphere is salty and corrosive.

General service conditions: a. Altitude: < 1,524 m (5,000 ft) b. Relative humidity (annual average): 80% c. Minimum temperature: 4.4°C d. Maximum temperature: 40°C e. Maximum 24-hour average temperature: 30°C f. Annual average temperature: 26°C g. Installation location: Within 30 m from the sea

1.3 Technical Specification

3000 kVA residential transformer box specifications type and data sheet

1.4 Drawings

3000 kVA residential transformer box diagram drawing and size.

02 Manufacturing

2.1 Core

The five-limb core design effectively reduces eddy current losses and hysteresis losses, improving transformer efficiency. The optimized magnetic circuit design results in significantly reduced electromagnetic noise during operation. The balanced three-phase magnetic circuit and the auxiliary limb’s magnetic path enhance the transformer’s ability to handle short-circuit conditions.

2.2 Winding

The transformer Winding is a closed loop composed of conductor copper, which is divided into high voltage (HV) winding and low voltage (LV) winding according to the function of the transformer. They are coupled with each other by electromagnetic induction to realize the conversion of electrical energy between different voltage levels. pad mounted transformer switches between YNyn0 and YNd11 connection modes, allowing the transformer to work in different application scenarios, such as power supply systems requiring neutral points (YNyn0) or industrial load scenarios requiring triangle windings to resist imbalance (YNd11).

2.3 Tank

Use high-quality carbon steel steel plates with a thickness of 3-6 mm, ensuring high strength and corrosion resistance. Cut the steel plates using laser or shearing machines to ensure precise dimensions, Employ CO₂ shielded welding or TIG welding, focusing on double-sided welding for critical seams. After cleaning and sandblasting, apply multi-layer coatings (anti-rust primer + corrosion-resistant topcoat) to ensure corrosion protection and aesthetic appeal. Conduct leak tests (e.g., nitrogen pressurization) and mechanical strength tests to ensure no leaks and adequate rigidity.

2.4 Pentahead Bolt

We provide a fully compliant captive pentahead bolt design integrated with the safety latch. Our enclosure prevents any padlocking unless the pentahead bolt is fully tightened. The entire locking mechanism is recessed for a tamper-resistant structure. The bolt remains captive to avoid removal or thread damage during door operation, even under forceful closing, and meets IEEE C57.12.28/34 requirements.

2.5 Final Assembly

Transformer Core: Comprising high-quality silicon steel core and windings for high and low voltage. Insulating Oil Chamber: Contains insulating oil for cooling and insulation. Line Components: High and low voltage terminals for cable connections, with waterproof and dustproof features. Accessories: Pressure relief valves, oil level indicators, temperature sensors, and grounding systems.

03 Testing

04 Packing and Shipping

05 Site And Summary

The three-phase pad-mounted transformer is a critical core device in modern power systems, widely used in various power distribution scenarios due to its outstanding performance and reliable safety features. Whether in bustling urban centers or remote rural areas, our transformers can flexibly meet various electricity demands, providing continuous and stable power support.

Our products undergo rigorous quality testing and are manufactured to high standards, ensuring reliable operation under extreme conditions without compromise. With innovative designs and advanced technology, our three-phase transformers not only enhance the efficiency of power transmission but also reduce maintenance costs and improve environmental adaptability, ensuring a strong return on investment for our users.

By choosing our residential transformer box, you are not only selecting an efficient and safe power solution but also laying a solid foundation for sustainable development in the future. Let us work together to advance the power distribution industry and build a smarter, greener future.