750 kVA Outdoor Pad Mounted Transformer-34.5/0.48 kV | USA 2024

Exquisite craftsmanship and excellent quality — the three-phase pad-mounted transformer supports efficient and stable power systems!

01 General

1.1 Project Description

750 kVA three phase pad mounted transformer was delivered to China in 2024. The rated power of the transformer is 750 kVA with ONAN cooling. The primary voltage is 34.5GrdY/19.92 kV with ±2*2.5% tapping range (NLTC), the secondary voltage is 0.277/0.48 kV, they formed a vector group of YNyn0.

The three-phase pad-mounted transformer has a closed design and is mounted on the ground, allowing for easy cable connections. The transformer’s enclosure is waterproof and dustproof, making it suitable for various weather conditions. It adopts the load break bushing which is a specialized device that enables maintenance and connections without interrupting the load current. This allows operators to safely connect and disconnect cables while the system remains energized, thereby enhancing the reliability and flexibility of the power grid. Three-phase pad-mounted transformers are equipped with various safety features, such as overload protection, short circuit protection, and temperature monitoring to ensure safe operation. Three phase pad transformers are widely used in urban and rural electrical distribution systems, providing reliable power support to meet the increasing demand for electricity.

1.2 Technical Specification

750 kVA transformer specifications type and data sheet

1.3 Drawings

750 kVA pad mounted transformer diagram drawing and size.

02 Manufacturing

2.1 Core

The core of a three-phase pad-mounted transformer employs a column-type design, consisting of multiple core legs assembled together to provide a large magnetic flux path. The design of the core is a closed loop, maximizing magnetic flux containment and ensuring efficient energy conversion between input and output. The core’s design typically utilizes a symmetrical arrangement to ensure balanced distribution of the three-phase currents, reducing noise and vibration during operation. The choice of core materials and design offers good thermal conductivity, helping to dissipate heat during operation and maintain optimal operating temperatures.

2.2 Winding

The winding consists of three sets of identical windings corresponding to the three-phase power supply (A, B, and C phases). This design ensures balance and functionality between each phase, helping provide stable three-phase power output. e windings are generally made from aluminum as the conductor materials. The windings are covered with insulation materials to prevent short circuits and leakage. High-quality winding designs can significantly reduce current losses and thermal losses, improving the overall efficiency of the transformer.

2.3 Tank

The tank is made of corrosion-resistant stainless steel to enhance its durability and strength, ensuring it can withstand the effects of internal oil pressure and external environment. The oil tank features a sealed design to prevent oil leakage, while also avoiding the ingress of moisture or impurities, thereby maintaining the stability and cleanliness of the oil. The transformer oil inside the tank has excellent insulating properties, effectively preventing electrical faults and leakage, ensuring the safe operation of the transformer. Tank is equipped with oil level gauges that provide real-time monitoring of the oil level, ensuring it remains within a normal range to maintain effective cooling. The oil tank design includes pressure relief valves to prevent excessive internal pressure that could lead to tank damage or explosion.

2.4 Final Assembly

Winding Installation: Install the tested windings inside the oil tank, ensuring they are correctly connected to the appropriate leads. Core Installation: Assemble and secure the core inside the oil tank to effectively couple with the windings. Oil Filling: After ensuring all internal components are properly installed, fill the oil tank with insulating oil to ensure the windings and core are completely submerged. Sealing and Testing: Seal the oil tank and conduct pressure and leakage tests to ensure there are no oil leaks. Electrical Wiring: Perform electrical wiring according to the electrical schematic, connecting the terminals for the high-voltage and low-voltage sides.

03 Testing

(1) Routine test

a) Ratio on connections and tap positions

b) Angular displacement

c) No-load losses at 100% rated voltage

d) Exciting current at 100% rated voltage

e) Lload losses and impedance at rated current

f) Applied voltage

g) Induced voltage

h) Transformer tank leak-detection test

i) A continuity test

(2) Type test

a) Resistance

b) Temperature rise

c) Impulse strength

d) Radio-influence voltage

f) Transformer integrity

g) Core audible sound

h) Negative pressure withstand

04 Packing and Shipping

05 Site And Summary

In summary, our three-phase pad-mounted transformer is engineered to deliver exceptional performance, reliability, and safety for your power distribution needs. With its robust construction, advanced insulation properties, and efficient cooling system, this transformer is designed to operate effectively in various environmental conditions. Whether you are looking to enhance urban infrastructure, commercial facilities, or industrial applications, our transformer offers a compact and versatile solution that meets the highest industry standards. Trust in our commitment to quality and innovation, and choose our three-phase pad-mounted transformer to ensure a stable and efficient power supply for your operations.