There are several key differences between dry-type and oil-immersed transformers. Understanding these differences can help you better choose the right transformer type. The following are their main differences:
Different Cooling Mediums
Oil-immersed transformers use oil as a cooling and insulating medium, while dry-type transformers use air or other gases as a cooling medium.
Application
Dry-type transformers typically only have voltage ratings up to 35 kV, and their manufacturing process is relatively complex and expensive. Therefore, oil-immersed transformers are currently more common on the market.
Cost and Maintenance
Oil-immersed transformers are cheaper and easier to maintain, but they carry the risk of flammability and explosion. Dry-type transformers are more expensive, larger, have poor moisture and dust resistance, are noisy, and also carry the risk of flammability and explosion.
Appearance and Internal Structure
Dry-type transformers lack an outer casing, allowing the coils to be visible. Oil-immersed transformers have an outer casing, but the coils are immersed in oil, making the internal coils invisible.
Radiator
Oil-immersed transformers have external radiators for heat dissipation, while dry-type transformers do not.
Installation Location
Oil-immersed transformers require fire protection and are typically installed in a separate transformer room or outdoors. Dry-type transformers, on the other hand, can be installed in a low-voltage distribution room, side by side with a low-voltage distribution cabinet.