Sola K4E2H45S - SolaHD K-Factor Transformers are engineered to mitigate the heating effects of harmonic currents generated by non-linear loads. These transformers have UL ratings of K-4, K-13, and K-20, indicating their capacity to handle harmonic content while staying within insulation temperature limits. The K-Factor design incorporates several key features, including conductors capable of carrying harmonic currents without exceeding insulation temperature ratings, consideration for "stray losses" resulting from non-linear loads, and core and coil design management of DC flux caused by triplen harmonics. These transformers are energy-efficient, UL 1561 Listed up to K-20 rated protection, have a rated temperature rise of 150°C, and 220°C insulation. They are also shielded for power quality, meet transit test requirements, and operate quietly.