HT instruments PQA824 - Manual (Page 92)

PQA400 - PQA823 - PQA824
EN - 91
This screen (Fig. 155) contemporarily shows the instant values of the waveforms of voltage
V31 and current I3, scaled according to the relevant Full scale (Fs) and the relevant RMS
values; these values have been saved by the instrument upon pressing the SAVE key.
Fig. 155: Phase 3 scope in three-phase 3-wire system or Aron system
The following keys are active on this page:
 The
F2 key (or the ZOOM V or ZOOM I item on the dislay) switches between voltage
zoom and current zoom (only if the manual zoom mode has been activated).
 The up (ZOOM+) or down (ZOOM-) arrow keys zoom in or out the displayed
waveforms (only if the manual zoom mode has been activated).
 The
F1 key (or the PAG item on the display) advances to the following page of
saved voltage values.
 The
ESC key (or the smart icon on the display) to exit the function and go back
to the “Recording analysis” page (Fig. 143).
5.5.2.3. Harmonics analysis
This screen (Fig. 156) 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 (not for PQA400) 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. 156: 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.