Three-Phase Oil-Immersed off-Circuit Tap Changer Power Transformers 35kV 38.5kV

Oil-Immersed Off-Circuit Power Transformers Product Overview

Three-Phase Oil-Immersed Off-Circuit Power Transformers 35kV/38.5kV are core distribution equipment designed for medium-voltage power grids, widely applied in industrial parks, urban power distribution networks, mining, and petrochemical fields. Three-Phase Oil-Immersed Off-Circuit Power Transformers adopt an oil-immersed insulation structure and off-circuit tap-changing technology, ensuring stable voltage output and reliable power supply for various loads. The product is optimized for 35kV and 38.5kV voltage levels, with a compact structural design that reduces installation space while meeting the strict operation requirements of medium-voltage systems. Three-Phase Oil-Immersed Off-Circuit Power Transformers feature excellent thermal stability and insulation performance, enabling long-term safe operation under rated load conditions. As a key component of power transmission and distribution systems, Three-Phase Oil-Immersed Off-Circuit Power Transformers effectively connect different voltage levels, supporting the efficient and stable operation of the entire power grid.

Oil-Immersed Off-Circuit Power Transformers Structural Features

• Superior Insulation Performance：Three-Phase Oil-Immersed Off-Circuit Power Transformers use high-quality insulating oil and graded insulation structures to achieve excellent dielectric strength, effectively resisting overvoltage impacts in 35kV/38.5kV systems. The fully sealed oil tank design of Three-Phase Oil-Immersed Off-Circuit Power Transformers prevents contact between insulating oil and air, avoiding moisture intrusion and oil aging, thus extending the service life of the equipment.
• Reliable Off-Circuit Tap-Changing Function：Three-Phase Oil-Immersed Off-Circuit Power Transformers are equipped with precision off-circuit tap changers, which can adjust the output voltage according to grid load changes after power outage. The tap changer has a reasonable gear design and stable contact performance, ensuring accurate voltage regulation and strong mechanical durability, which meets the voltage adjustment needs of different operating scenarios of the power grid.
• Efficient Heat Dissipation System：Three-Phase Oil-Immersed Off-Circuit Power Transformers adopt corrugated oil tank or radiator-type heat dissipation structures, which can quickly dissipate the heat generated during operation, maintaining the top oil temperature within a safe range. This heat dissipation design ensures that Three-Phase Oil-Immersed Off-Circuit Power Transformers can operate stably for a long time under high-load conditions, with low loss and high efficiency.
• Strong Environmental Adaptability：Three-Phase Oil-Immersed Off-Circuit Power Transformers have good corrosion resistance, and the tank surface is treated with anti-corrosion coating, which can adapt to harsh environments such as humidity, dust, and salt mist. Whether in coastal areas or industrial sites with heavy pollution, Three-Phase Oil-Immersed Off-Circuit Power Transformers can maintain stable performance, with low maintenance costs and strong operational reliability.
• The S9 series complies with IEC 60076 (formerly IEC 76) standards. It features low losses, low noise, and low partial discharge. The transformer offers high electrical and mechanical strength, is leak-proof, and requires no maintenance—delivering excellent economic and social benefits.

Compliance Standards

a) GB 1094.1 & GB 1094.2–2013: Power Transformers

b) GB 1094.3–2003 & GB 1094.5–2008: Power Transformers

c) GB/T 6451–2015: Technical Parameters and Requirements for Oil-Immersed Power Transformers

d)IEC 60076-2, IEC 60076-4, and IEC 60076-19 Power Transformers

Model Designation and Its Meaning

• Installation Type: Outdoor
• Ambient Temperature: Maximum +40°C, Minimum –25°C
• Altitude: Up to 1,000 m above sea level
• Relative Humidity: ≤90% at +25°C
• Installation Environment: Free from corrosive gases and heavy pollution
• Primary Applications: Industrial power systems and transmission & distribution projects