ECN Forum Forums General Topics of the Trade General Discussion Area Quiet type transformers

There is some general information at http://www.federalpacific.com/university/transnoise/transnoise.html http://www.federalpacific.com/literature/drytrans/FPTS-UTN-0900.pdf
{Note this is not FPE—the “breaker” guys}

If the transformer has a harmonic-current [a/k/a "nonlinear"] load, acoustic noise may increase.