Dry-type transformers are widely used in local lighting, high-rise buildings, airports, docks, and CNC machinery. Simply put, a dry-type transformer is one whose core and windings are not immersed in insulating oil.
1. Open type: This is a common type where the transformer body is in direct contact with the atmosphere. It is suitable for relatively dry and clean indoor environments (relative humidity should not exceed 85% at an ambient temperature of 20 degrees Celsius). It generally uses either air self-cooling or air cooling.
2. Enclosed type: The transformer body is located in a closed casing and is not in direct contact with the atmosphere (due to poor sealing and heat dissipation, it is mainly used in mining and is classified as explosion-proof).
3. Cast resin type: Epoxy resin or other resins are used as the main insulation. It has a simple structure and small size, suitable for smaller capacity transformers.