Technology Literature

Which one is dry-type transformer or oil-immersed transformer right for you?

Transformers are common and useful devices that take high-voltage electricity directly from power stations and convert it to lower voltages. This enables the safe and efficient use of energy only by machinery and appliances that handle low voltages in spaces such as offices, transportation hubs, schools and factories.

Through this process, transformers generate a lot of heat that must be dissipated in order for them to operate safely. There are two types of transformers currently used in industry: dry-type transformers and oil-immersed transformers. The dry type uses air as the cooling medium, and the liquid cooling uses oil. While the end result is the same for both types, there are a number of notable differences between them that will affect which type you choose.

Maintenance: Oil-cooled transformers require more maintenance procedures and must be performed more frequently than dry-type transformers. Oil needs to be sampled to test for contamination, and dry-type transformers are very resistant to chemical contamination.

Cost (initial and operating): Dry has significantly higher operating losses compared to oil cooling. Oil-immersed transformers have a higher standard energy efficiency and therefore have a higher service life than dry-type transformers.

Noise: The operating sound level of oil-cooled transformers is lower, so the noise pollution is less than that of dry-type transformers.

Recyclability: Dry end-of-life recycling is limited, while oil units have easier core/coil recycling. Oil-cooled with superior longevity and maintainability, producing less waste and requiring less replacement and labor.

Efficiency: Dry-type transformers are larger units with limited voltage and size, making them more prone to overheating if they experience overload. As a result, they have higher electrical losses and are more expensive to maintain dry power over time. Oil-cooled units are smaller and more efficient. They require less demand and create a smaller environmental footprint.

Voltage Capability: Dry-type transformers are designed to handle small to medium MVAs and voltage ratings, making them ideal for small applications. Oil-cooled transformers can handle heavier loads, so applications requiring higher voltages will require oil units.

Location: The location of the transformer will be the biggest determinant of which type you need. Dry are designated for use in and near buildings simply because they are safer for the environment. Dry-type transformers are non-flammable and have less fire risk, making them ideal for shopping malls, hospitals, residential areas and other commercial areas. Oil-cooled transformers are used for outdoor installations because of the potential risk of fire due to oil leaks and spills, but these installations are more environmentally friendly.

Considering these variables, petroleum installations appear to be the better option overall, with higher energy efficiency, recyclability, lower noise pollution, lower operating costs and a smaller environmental footprint. However, the oil unit cannot be used in any situation at all. Dry are the best choice for commercial and indoor operations and are many times required because they are safer units to operate around people and areas that may present a fire hazard.

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