Nearly all of the well-known Switchgear and MCC Manufacturers have Power Quality plus Harmonic Distortion Instructional Documents available on-line...
and for FREE!!! smile thumbs

Check out websites for:

Siemens,
Square D,
Eaton,
Allen-Bradley,
Bussman,
etc.

Also check out some of the Transformer Manufacturers for descriptions of "Triple-N" Harmonics and K-Ratings for Transformers.

-- Scott (EE)

Scott " 35 " Thompson
Just Say NO To Green Eggs And Ham!