HT instruments VEGA78 - Manual (Page 79)

VEGA78
EN - 77
5.5.2.3. Harmonics analysis
This screen (Fig. 137) displays the harmonic values and the THD% value of voltages V1, V2,
V3, Vn and of currents I1, I2, I3 and of Neutral current In 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. 137: Total harmonics in three-phase 4-wire 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, relative to phase 1 harmonics.
 The
F2 key (or the ARM V or ARM I item on the dislay) 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).