User's Manual

PC Software for 1740 Series
PQ Log Feature Reference
41
Print
Click this button to print the selected measurement period using the default settings, or
with the desired start time and period setting.
Click S, to view details such as the interval information, including number of intervals,
voltage (V) and current (I) overflow, as well as power supply failure (N). (G) signifies a
valid measurement interval. (C), a clamp error, signifies the type of the current sensor
changed during a measurement.
Note
Values that are out of the measurement range are marked with the symbol
‘>’ on the left side of the numeric value.
Correlations of Voltages and Currents
The voltage and current values can be used to get information about sources of
disturbances in the power network. The relation between the extreme voltage values
(V
max
, V
min
) and the actual phase currents can be seen. On the other hand, the voltage at
the time of the maximum current is recorded simultaneously.
Within each measuring interval (example 10 min), the extreme values of the mains
voltage (V
min act
, V
max act
) based on 10 ms rms values are recorded.
Exactly at the time of the occurrence of these extreme voltage values (V
max act
, V
min act
),
the phase currents (I
act at Vmax
, I
act at Vmin
) are stored. On the other hand, at the time of the
maximum current (I
max act
) the actual pending voltage (V
act at Imax
) is stored. All of these
parameters can be evaluated graphically in the timeplot or numerically in the
measurement value tables. Export with all other interval values is possible.
Note
The extreme values (I
max act
, V
max act
, V
min act
) are always based on 10 ms rms
values, independent of the averaging time preset in the job 1/2-cycle up to
5 s).
Events
The UNIPEDE DISDIP table is used for the classification of voltage dips. The events are
sorted by their duration and deviation from the nominal value, and their quantities are
listed in the corresponding fields. An extended UNIPEDE DISDIP table can be found in
the corresponding analysis in PQ Log. In addition, voltage interruptions and surges are
also displayed. The part of DISDIP table defined by UNIPEDE is marked with a frame.