Understanding Transformer Maintenance: The Role of Desiccant Breathers and Preservation Systems

Transformers play a crucial role in electrical systems, and maintaining their functionality involves several key components, including desiccant breathers and liquid-preservation systems. Desiccant breathers utilize materials like silica gel to filter moisture from the air entering and exiting the transformer tank. This process is essential to ensure that the air quality inside the transformer remains optimal, thereby reducing the risk of moisture-related damage. When properly maintained, desiccant breathers can significantly enhance the longevity and performance of transformers.

Liquid-preservation systems are designed to safeguard the properties of transformer liquids and the insulation structures they penetrate. Unlike older free-breathing systems, which exposed transformer liquids to the atmosphere, modern systems aim to isolate the internal environment from external conditions. This isolation is vital as it allows transformers to respond to pressure variations caused by temperature changes without compromising their internal integrity.

Sealed-tank systems are one of the predominant preservation methods. In these systems, the tank's interior is hermetically sealed from the atmosphere, maintaining a constant volume of gas above the liquid. This design can result in negative internal pressures at lower loads or temperatures, transitioning to positive pressures as load and temperatures rise. Positive-pressure systems further enhance this safeguard by using inert gases, such as compressed nitrogen, to maintain adequate pressure levels.

Conservator systems, which feature auxiliary tanks known as expansion tanks, provide additional flexibility. These tanks are partially filled with liquid, allowing for expansion and contraction as temperatures fluctuate. The primary transformer tank remains filled, while the auxiliary tank can "breathe" through a dehydrating breather, ensuring moisture is filtered out before any air enters.

For enhanced protection, transformers equipped with conservator liquid-preservation systems can also incorporate devices like the “Buchholz” relay. This relay detects potential faults by monitoring gas accumulation within the transformer. Should a fault occur, the accumulated gases displace the transformer liquid, triggering an alert. The gas-accumulator relay performs a similar function, collecting gases generated during faults to signal when necessary.

Overall, understanding the function and importance of desiccant breathers and preservation systems is crucial for anyone involved in transformer maintenance. By effectively controlling the internal environment of transformers, these systems not only protect the equipment but also ensure reliable electrical operations.