What is a Harmonic Mitigating Transformer and how is it different than a K-Rated Transformer?
Harmonic Mitigating Transformers, or HMTs, are specifically designed to minimize the voltage distortion and power losses that result from the harmonics generated by non-linear loads such as personal computers. The accomplish this through the use of a zig-zag winding.
K-rated transformers, on the other hand, are simply designed to prevent their overheating when subjected to heavy non-linear loading, but do very little to reduce the harmonic losses themselves. And as for voltage distortion, K-rated transformers perform the same as conventional general purpose delta-wye transformers.