HT instruments VEGA78 - Manual (Page 89)

VEGA78
EN - 87
This screen (Fig. 147) displays the harmonic values and the THD% value of neutral
voltage Vn 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. 147: Voltage 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 dislay) switches between voltage and
current harmonics relative to Phase 1.
 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).