The large peak in the remaining edge of the spectrum plot is definitely the sixty Hz fundamental. The massive harmonic peaks you see demonstrate that my wall electrical power here isn't really Tremendous-clean up. If your only defense is aged surge protectors with fried MOVs, you won't have any safety. https://myleswuwoh.sharebyblog.com/33744245/the-smart-trick-of-ups-ups-that-nobody-is-discussing