Harmonic Distortion - THD vs Rule Limit

Total Harmonic Distortion assessment vs class rule / IEC 61000 limits - typical 5 % voltage / 8 % current on marine distribution.

HarmonicTHDIEC 61000

Voltage THD%Current THD%

Status: Exceeds - add harmonic filter or 6→12-pulse drive conversion

Changing the inputs requires JavaScript. The calculator above shows its default inputs and result. The formula, symbols, and regulatory sources are shown in the Formula section below.

Formula, assumptions, and limits

THD_V \leq 5\%, \quad THD_I \leq 8\%

Symbol	Meaning	Unit
$THD_V$	Voltage total harmonic distortion	%
$THD_I$	Current total harmonic distortion	%

Source: IEC 61000-3-4 / Class rules

In short

Total Harmonic Distortion assessment vs class rule / IEC 61000 limits - typical 5 % voltage / 8 % current on marine distribution.

Learn the theory Marine Electrical Generation and Distribution