WAGO-I/O-SYSTEM 750 Function Description 39750-494 3-Phase Power Measurement ModuleManualVersion 1.2.0frequency and current are no longer possible. The measuring accuracy of allcurrent-depending variables (current, power, energy) falls off by 0.4%.3. Near the ZC limit, the accuracy of the phase angle measurement decreasesto a value of ± 1.5 °.4. If a current measuring input operates near no-load, higher measuring errorscan occur for this measuring path.5. Measuring errors due to input overdrive:When the input current or input voltage exceeds the nominal values for theI/O module, input overdrive is produced (see figure below). The I/O modulecannot digitize these values and limits the measured values to the maximummeasurable range (clipping of the current or voltage measured values). As aresult, the RMS value that is output is erroneous. The more the input isoverdriven (and, thus, the reference points for RMS calculation), the greaterthe measuring error.Clipping of the voltage or current values is displayed via the expandedstatus word 1 in the process image and by LED C (current) or LED G(voltage) in diagnostics.Figure 10: Input Overdrive (Clipping)For DC measurements, the error is <= 1% of the full-scale value for current,voltage and power.Pos : 76 /D okumentation allgemei n/Glieder ungs elemente/---Seitenwechs el--- @ 3\mod_1221108045078_0.doc x @ 21810 @ @ 1
