Hevi-Duty low temperature rise transformers feature a 220°C insulation system and temperature rise of only 80°C or 115°C under full nameplate load. The result is 13-21% lower operating losses than conventional 150° rise units. Reduction in temperature rise increases reliability. The 35oC thermal reserve on 115°C rise units and 70°C reserve on 80°C rise units definitely mean lower operating costs.