These high-efficiency isolation transformers have been designed to provide a higher degree of isolation (as measured by leakage current to ground), improved efficiency and reduced size and weight. Increased efficiency results in cooler operation, allowing these transformers to be installed in sealed environments with no external cooling. The transformers offer full-load operating efficiencies of 97% to 99%. More than 250 models are available covering input voltage ranging from 120 through 600 V and secondary voltages of 120, 208, 240 or 277 V.