Amprobe Multitest-2000 Continuity-Tester - Manual (Page 169)

AMPROBE
MULTITEST2000
the increasing of power losses due to harmonics is added to that introduced by the
presence of reactive power. In effect, even if the two phenomena contribute together to the
increase of power losses in line, it is not true in general that these causes of the power
losses are in phase between each other and therefore that can be added one to the other
mathematically.
The above given relation is justified by the relative simplicity of calculation of the same and
by the relative discrepancy between the values obtained using this relation and the true
value.
It is to be noted moreover, how in case of an electric installation with harmonics, another
parameter called distorted Power Factor (dPF) is defined. In practice, this parameter
represents the theoretical limit value that can be reached for Power Factor if all the
harmonics could be eliminated from the electric installation.