Insulation & Cooling
Dry-type: Uses air or epoxy resin insulation, cooled by natural air or fans. No oil leakage risk but lower cooling efficiency.
Oil-immersed: Relies on insulating oil for cooling, with strong heat dissipation via oil circulation. Suited for high loads but risks oil leakage and fire hazards.
Safety & Environmental Impact
Dry-type: Fireproof and explosion-proof, ideal for fire-sensitive areas (e.g., hospitals, data centers). No pollution.
Oil-immersed: Requires periodic oil changes, with potential environmental contamination from waste oil, but offers higher short-circuit resistance.
Typical Applications
Dry-type: Indoor use, confined spaces, or high-fire-risk zones (e.g., subways, commercial buildings).
Oil-immersed: Outdoor, high-capacity, high-voltage scenarios (e.g., power plants, industrial parks).
Cost & Maintenance
Dry-type: 30-50% higher upfront cost but lower maintenance and longer lifespan.
Oil-immersed: Lower initial cost but higher long-term maintenance due to oil replacement.
Summary: Choose dry-type for safety-critical environments, oil-immersed for high-capacity needs.
