Transformers play a vital role in power distribution by stepping up or stepping down voltage levels to ensure efficient electricity transmission. However, maintaining transformer efficiency and longevity requires proper care of its insulating oil and internal components. One crucial component in this process is the breather in transformer.
The breather in transformers is essential in protecting the transformer oil from contamination and moisture, ensuring the smooth operation of the electrical system. This blog will explore what is breather in transformers, its function, importance, and working principle in detail.
What is Breather in Transformer?
A breather in transformers is a device used to maintain the quality of transformer oil by preventing moisture from entering the tank. It is typically a cylindrical container filled with silica gel, which absorbs moisture from the air before it enters the transformer.
Since transformers undergo heating and cooling cycles, they tend to inhale and exhale air due to oil expansion and contraction. The breather in transformers ensures that the air entering is dry, preventing the deterioration of insulation and internal components.
Why Breather is Used in Transformer?
Transformers use insulating oil for cooling and insulation. However, exposure to moisture can degrade the oil’s dielectric strength, leading to reduced efficiency and potential failure. The breather in transformer is used for the following reasons:
- Prevent Moisture Contamination: Moisture in transformer oil can cause insulation breakdown, leading to short circuits or equipment failure. The breather in transformers ensures that only dry air enters the system.
- Enhance Transformer Longevity: By keeping the insulation oil dry and clean, the breather helps extend the transformer’s lifespan.
- Improve Electrical Performance: Moisture-free insulation oil maintains the electrical properties of the transformer, ensuring uninterrupted power distribution.
- Prevent Corrosion: Moisture can lead to corrosion of internal transformer components. The breather in transformers prevents this by filtering out humidity.
Function of Breather in Transformer
The function of breather in transformers is to remove moisture from the air before it enters the transformer, ensuring the quality of the insulating oil remains intact. The key functions of the breather include:
- Air Filtration: The breather filters out dust and contaminants from the air drawn into the transformer.
- Moisture Absorption: The silica gel inside the breather absorbs moisture from incoming air, keeping the transformer oil dry.
- Pressure Regulation: During transformer operation, the breather allows air to move in and out, balancing internal pressure while keeping the oil uncontaminated.
Visual Indication of - Moisture Absorption: Most breathers have colour-changing silica gel, which shifts from blue to pink as it absorbs moisture, signalling when replacement is needed.
Working Principle of Breather in Transformer
The working principle of breather in transformers revolves around its ability to filter and dehumidify the air entering the transformer. Here’s a step-by-step breakdown:
- Oil Expansion and Contraction: When the transformer is operational, the temperature rises, causing the insulating oil to expand. This forces air out of the conservator tank.
- Air Inhalation During Cooling: As the transformer cools down, the oil contracts, creating a vacuum that pulls in external air.
- Moisture Filtration: The incoming air passes through the breather, where silica gel absorbs moisture before it enters the transformer tank.
- Silica Gel Color Indication: Over time, as silica gel absorbs moisture, it changes colour from blue to pink, indicating saturation and the need for replacement or regeneration.
Types of Breathers Used in Transformers
There are different types of breathers designed for transformers based on their applications and capacity:
1. Conventional Silica Gel Breather
This is the most commonly used breather in transformers, consisting of a transparent chamber filled with silica gel that absorbs moisture from the air.
2. Self-Dehydrating Breather
A self-dehydrating breather automatically regenerates silica gel by heating it, removing absorbed moisture, and extending its usability. This type is often used in large transformers.
3. Oil-Sealed Breather
Some breathers use an oil trap to remove dust and contaminants before the air passes through the silica gel, providing an additional layer of filtration.
Maintenance of Breather in Transformer
Regular maintenance of the breather in transformers is essential to ensure its proper functioning. Here are key maintenance steps:
- Monitor Silica Gel Color: Replace or regenerate silica gel when it turns pink, as it indicates moisture saturation.
- Check for Blockages: Ensure the air passage is clear and free of dust or dirt accumulation.
- Inspect the Seals and Gaskets: Any leaks can reduce the effectiveness of the breather, allowing moisture to enter the transformer.
- Replace Worn-Out Components: If the breather’s casing or filter is damaged, replace it immediately to maintain efficiency.
Conclusion
The breather in transformers plays a vital role in maintaining transformer efficiency by preventing moisture contamination of the insulating oil. Understanding what is breather in transformer, the function of breather in transformer, and why breather is used in transformers highlights its importance in prolonging transformer life and ensuring uninterrupted power distribution.
Regular maintenance of the breather is essential to keep transformers functioning optimally. By replacing silica gel when needed and ensuring proper airflow, operators can protect their transformers from insulation breakdown and performance degradation.
With advancements in transformer technology, improved breathers, such as self-dehydrating models, are enhancing moisture control, ensuring transformers remain reliable in modern power systems.
