ABB's Guard III Harmonic Mitigating Transformers (HMT) help eliminate harmonics, improve power quality, and help save energy by reducing the energy (heating) losses associated with harmonic activity. They maintain DOE 2016 energy efficiency even when harmonics are present. The HMT's are UL Listed and are available in common phase shifts with zigzag transformer secondaries. Qualified to the seismic requirements of IEEE-693-2005 and IBC-2021 and CBC 2022.