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69KV 30MVA 3 Phase Power Transformer

The 69kV 30MVA three-phase power transformer is a high-performance unit designed for efficient and reliable power distribution in medium- to large-scale substations. With a primary voltage rating of 69 kV and a secondary voltage of 13.8 kV, it is engineered to handle substantial electrical loads. The transformer features a three-phase, dual-winding core type structure, ensuring stable and continuous operation under varying load conditions. It employs an oil-immersed cooling system, utilizing natural air cooling (ONAN) under normal conditions and enhanced fan-assisted cooling (ONAF) during peak loads, to maintain optimal temperature levels. On-load voltage regulation is facilitated through a ±8 × 1.25% tap range, allowing for precise adjustments to accommodate fluctuations in the power supply. Built with high-quality materials and advanced design principles, this transformer offers robust performance and longevity, even in challenging environmental conditions. Its compliance with international standards ensures safety and reliability in power distribution applications.

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Product Accessories

72.5 kV High Voltage Bushings: Facilitate secure and efficient high-voltage connections.

25 kV Pure Porcelain Low Voltage Bushings: Ensure durability and reliability in low-voltage connections.

Oil Conservator: Maintains oil levels and accommodates thermal expansion.

Tap Changer: Allows for on-load voltage regulation, enhancing system stability.

Temperature Indicator: Monitors oil and winding temperatures to prevent overheating.

Pressure Relief Device: Protects the transformer from internal pressure build-up.

Oil Drain Valve: Facilitates safe and efficient oil changes.

Stainless Steel Nameplates: Provide clear identification and compliance information.

Fan: Enhances cooling efficiency under high-load conditions.

Stainless Steel Wind Control Box: Protects electrical components from environmental factors.

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Product Specifications

Rated Capacity

30MVA (ONAN)

Primary Voltage

69 kV

Secondary Voltage

13.8 kV

Frequency

60 Hz

Vector Group

YNhd

Impedance Voltage

10.34% at 35 MVA

No-load Losses

110 kW

Load Losses

32 kW

Noise Level

58 dB

Standards Compliance

Conforms to IEC 60076 ANSI and IEEE specifications

Product Applications

Economy is more affordable

Ideal for medium- to large-scale substations requiring reliable voltage step-down from 69 kV to 13.8 kV.

Substation Power Distribution
Supports manufacturing facilities with high power demands, ensuring stable and efficient energy supply.

Industrial Power Supply
Facilitates the connection of renewable energy sources to the grid, accommodating variable power inputs.

Renewable Energy Integration
Enhances the reliability of urban power grids, supporting residential and commercial energy needs.

Urban Power Infrastructure

Product Advantages

Efficient Cooling System

The ONAN/ONAF cooling method ensures optimal temperature regulation, enhancing transformer longevity and performance.

Advanced Voltage Regulation

The on-load tap changer provides ±8 × 1.25% voltage regulation, maintaining stable output under varying load conditions.

Robust Insulation Design

High insulation levels (360 kV full-wave lightning impulse) protect against electrical surges, ensuring transformer durability and reliability.

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.