Final answer:
Enclosures are used to make dry-type distribution transformers weather resistant for outdoor installations, protecting them from moisture and environmental factors.
Step-by-step explanation:
Enclosures are installed on dry-type distribution transformers to make them weather resistant and suitable for outdoor installations. Unlike transformers designed strictly for indoor use, outdoor transformers must be able to withstand various weather conditions, such as rain, snow, and extreme temperatures. An enclosure for a dry-type distribution transformer is typically made of materials that prevent moisture from entering and protect the transformer's components from corrosion and other environmental factors. These enclosures can range from simple weather shields to more complex structures offering protection against vandalism and unauthorized access.