HT instruments VEGA78 - Manual (Page 81)

VEGA78
EN - 79
This screen (Fig. 139) displays the harmonic values and the THD% value of voltage V1
and current I1 in a graph (scaled according to the Full scale Fs) or in a table. The values
displayed are percentage values of the fundamental or absolute values according to the
configuration set in the ANALYZER CONFIGURATION MENU -> ADVANCED.
Fig. 139: Phase 1 harmonics in single-phase system
Should only the voltage signals or only the current signals be connected to the instrument’s
inputs, all displayed harmonics will be shown in the upper half plane of the graph.
If both voltage and current signals are connected to the instrument’s inputs, the histogram bars
representing the harmonics will be shown respectively:
 In the upper half plane of the graph if the harmonics are introduced into the relevant
electrical system from the mains.
 In the lower half plane of the graph if the harmonics are injected into the relevant electrical
system from the mains.
The following keys are active on this page:
 The up (ZOOM+) or down (ZOOM-) arrow keys zoom in or out the histogram.
 The right and left arrow keys move the cursor to the right or to the left along the
harmonics.
 The F1 key (or the PAG item on the display) advances to the following page of saved
values (only for voltage harmonics).
 The
F2 key (or the ARM V or ARM I item on the display) switches between total voltage
and current harmonics.
 The F4 key (or the ARM PAG item on the display) displays the following harmonics
group. 0..9, 10..19, 20..29, 30..39, 40..49.
 The ESC key (or the smart icon on the display) to exit the function and go back to the
“Recording analysis” page (Fig. 124).