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11KV 800KVA Three Phase Low Loss Distribution Transformer

11KV 800KVA Three Phase Low Loss Distribution Transformer

Engineered to meet modern power demands, the 11KV 800KVA Three Phase Low Loss Distribution Transformer is built with advanced oil-immersed technology that dramatically minimizes both no-load and load losses. Precision-engineered with high-performance oxygen-free copper windings and a robust core structure, it ensures uniform magnetic flux and outstanding voltage regulation. The fully sealed design and efficient ONAN natural cooling system—with integrated corrugated radiators—provide superior thermal management and extend the transformer's operational life. Ideal for urban distribution networks and demanding industrial applications, this transformer delivers stable, high-quality power under fluctuating loads, while its enhanced safety features and low noise output make it a reliable, environmentally friendly solution for next-generation power systems.

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Product Accessories

Core Construction
The transformer core is constructed from high-quality cold-rolled silicon steel sheets, optimized with a three-phase core-type design to enhance magnetic coupling and reduce leakage flux, thereby improving efficiency. The core is fully sealed to minimize oxidation and vibration-induced noise, achieving sound levels as low as 30-45 decibels.

Windings
Both high-voltage (11kV) and low-voltage (0.4kV) windings are wound with insulated copper conductors. The high-voltage windings typically adopt the Dyn11 vector group connection, with the outer layers insulated using materials such as grid-reinforced adhesive paper to ensure concentricity and mechanical strength. The windings are arranged concentrically, with the low-voltage winding positioned internally and the high-voltage winding externally, reducing electromagnetic interference. An insulating sleeve separates the windings from the core, enhancing electrical isolation and safety.

Oil Tank
The transformer features a fully sealed corrugated oil tank design, preventing oil evaporation and external contamination. The corrugated structure allows the tank to accommodate oil volume changes due to temperature variations, minimizing maintenance requirements. The tank is filled with transformer oil, such as 25# or 45#, which serves both insulating and cooling purposes. Oil circulation is facilitated through natural convection or, in certain models, by forced cooling devices to enhance heat dissipation.

Cooling System
The transformer primarily utilizes oil-immersed natural air cooling (ONAN). Some models may be equipped with corrugated radiators or tubular radiators to further improve heat dissipation efficiency, ensuring optimal operating temperatures and extending service life.

Insulating Bushings
Both high-voltage and low-voltage sides are equipped with porcelain insulating bushings, which serve to connect internal leads to external circuits while providing ground insulation. The high-voltage bushings are designed taller than the low-voltage bushings to accommodate different electrical stresses and mechanical requirements.

Tap Changer
The transformer is equipped with a no-load tap changer (NLTC) that allows for voltage regulation by adjusting the number of turns in the high-voltage winding. Typically, the tap changer offers voltage adjustment ranges of ±5% or ±2×2.5%, facilitating manual voltage setting to accommodate grid voltage fluctuations and ensure stable operation.

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Product Specifications

Rated Voltage

High-voltage side: 11kV ±5%

Low-voltage side: 0.4kV

Capacity

800KVA

No-load Loss (P₀)

≤700W

Load Loss (Pₖ)

≤7500W

Short-circuit Impedance (Uk%)

4.5% or 6% (optional)

Connection Group

Dyn11 or Yyn0

Cooling Method

ONAN (Oil-Immersed Natural Air Cooling)

Insulation Level

High-voltage side: Lightning Impulse (LI) 75kV / AC Withstand Voltage 35kV

Low-voltage side: LI 35kV / AC Withstand Voltage 5kV

Noise Level

≤55dB(A) (no-load, at 1m distance)

Compliance

Meets IEC 60076 ANSI and IEEE standards

Product Applications

Economy is more affordable

The S13 11kV 800kVA transformer efficiently delivers stable power to manufacturing plants, ensuring seamless operation of machinery and equipment.

Industrial Manufacturing Facilities
Designed to meet the energy demands of commercial buildings, this transformer supports lighting, HVAC systems, and other essential services.

Commercial Complexes
Ideal for connecting renewable energy sources, such as solar or wind power, to the grid, facilitating efficient energy distribution.

Renewable Energy Integration
Provides reliable and continuous power to data centers, safeguarding against outages and maintaining optimal performance of servers and networking equipment.

Data Centers

Product Advantages

Enhanced Energy Efficiency

Incorporating advanced design features, the transformer minimizes energy losses, resulting in reduced operational costs and improved sustainability.

Flexible Voltage Regulation

Equipped with a ±5% tap changer, it adeptly adjusts to voltage fluctuations, ensuring consistent and reliable power delivery across varying load conditions.

Compact and Durable Design

The transformer’s robust construction and sealed corrugated oil tank design not only save space but also extend service life by protecting internal components from environmental factors.

WellDone Power Transformer Plan Drawing

FAQ

What range of transformer products do you offer and which standards do they meet?

We manufacture a diverse array of transformers including Oil-Immersed Distribution Transformers, Dry Type Transformers, Power Transformers, Three Phase Pad Mounted Transformers, Single Phase Pad Mounted Transformers, Substation Transformers, and Pole Mounted Transformers. Our technical team, with nearly 20 years of industry experience, ensures that our designs comply with international standards such as ANSI, IEEE, DOE, CSA, AS, AZS, GOST, IEC, and more. Additionally, many of our products have obtained UL, cUL, and CSA certifications, affirming their safety and performance in global markets.
How do you ensure the quality and reliability of your transformers?

Our transformers are produced under a rigorous quality management system covering every stage from material selection to final testing. Each product comes with a minimum 24-month warranty, ensuring long-term safety and reliability. This commitment to quality has earned the trust of global customers and leading industry players.
What are your production lead times, customization options, and global market reach?

For standard models, our production lead time is typically 10 to 25 days, and we offer flexible OEM/ODM services for customized projects. We also tailor packaging solutions to meet specific customer requirements. Our transformers are exported worldwide—including North America, Europe, South America, Australia, Asia, and Africa—with successful partnerships involving renowned companies. For more details or personalized support, please contact us via email or WhatsApp.