Manual
Issue 1.3
23
8
Measurement principles and measured quantities
To determine the power quality parameters, ibaPQU-S measures raw values such as
currents and voltages in synch with the grid. The characteristic values relevant for power
quality are calculated internally.
8.1
Grid types
The device is suitable for 1-phase grids, 3-phase grids without neutral conductor and
3-phase grids with neutral conductor (N) or protective earth (PE).
Figure 9:
Different grid types
1-phase grid
In the 1-phase grid, the voltage U1 and the current I1 are measured.
3-phase grid without N/PE
The phase-to-phase voltages U12, U23, U31 and the phase currents I1, I2 and I3 (see
above illustration) are measured in this grid.
3-phase grid with N/PE
The phase voltages U1, U2, U3 and the phase currents I1, I2 and I3 are measured in
this grid. Optionally, UN and IN can be measured. (see above illustration)