How to Choose a Transformer: Dry Type vs. Oil Cooled

How to Choose a Transformer: Dry Type vs. Oil Cooled

Transformers are common and useful devices which take high voltage electricity directly from a power station and convert it to a lower voltage. This

allows the energy to be safely and efficiently used by machinery and appliances that can only handle low voltage in spaces such as offices, transportation

hubs, schools and factories.

Through this process transformers generate a lot of heat that must be dissipated to keep them running safely. There are two types of transformers being

used in the industry currently: Dry-type transformers and oil-cooled transformers. Dry-type uses air as a cooling medium, and liquid cooled uses oil.

Although both types have the same end result there are a number of differences between them worth noting, that will affect which type you choose.

Maintenance: Oil cooled transformers required more maintenance procedures, which must be performed more often than dry-type. The oil needs to be sampled

to test for contamination, whereas dry type transformer is very resistant to

chemical contaminants.

Costs (Initial and Operating): Compared to oil cooled, dry type has a significantly higher operating loss. Oil filled transformers have a higher standard

energy efficiency, and as a result have a higher lifespan than dry type.

Noise: Oil cooled transformers have a lower operating sound level, thus less noise pollution than dry-type.

Recyclability: The end of life recycling for dry type is limited, while oil units boast an easier core/coil reclamation. Oil cooled have superior

operating life and maintainability, producing less waste and requiring less replacements and labor.

Efficiency: Dry type transformers are larger units, limited in voltage and size, making them more prone to overheating if they experience overload. As a

result, they have higher electrical losses, and it is more expensive to maintain dry type power supply over time. Oil cooled units are smaller and more

efficient. They require less demand and create a smaller environmental footprint.