It is easy to distinguish from appearances.
The biggest difference between Oil immersed power transformer
and dry type transformer is there’s "oil" or not, and the oil is liquid, it can liquid, so the oil-immersed transformer must have the shell, the shell is internal transformer oil, soaked in oil of the transformer coil, the transformer coil cannot be seen from the outside; But the dry type transformer has no oil, does not need the shell, can see the transformer coil directly; Another feature is that the oil immersed power transformer has an oil pillow on top, and the transformer oil is stored inside. However, modern oil-immersed transformers are also produced without oil pillow.
Advantage of oil immersed power transformer
In order to help the oil-immersed transformer convenience for heat dissipation, which is convenient for the flow of the internal insulation oil cooling, the external design of radiator, just as a heat sink, and the dry type transformer is don't have the radiator, radiator on transformer coil below the fan, the fan is a bit like the indoor machine of household air conditioner;
because of the need of fire prevention, Oil immersed power transformer generally is installed in a separate transformer indoor or outdoor, and dry type transformer must be installed indoors, generally installed in the low-voltage distribution room, and low-voltage distribution cabinet side by side installation