Offered in 250+ models, isolation transformers feature full load operating efficiencies of 97%–99%. This enables cool operation as well as use in sealed panels without external cooling, while size and weight allow thinner panel construction. Inputs range from 120–600 V, 50/60 Hz, while available outputs include 120, 208, 240, or 277 V with ratings from 1.0–25.0 kVA. Three transformers can be connected in one bank for 3-phase operations.