User manual

PQM-702, PQM-703 Operating Manual

Selecting the right averaging time is not easy. To a large extent it depends on the type of dis-

turbance in the system and the user's expectations for the final data analysis. A frequent situation

is that we know only that there is a problem in the mains, and the measurements with the analyzer

will only help us identify the cause. In this situation it is better to use shorter averaging times (e.g.

10 seconds), and activate the recording of minimum and maximum values (for the voltages and

currents it is advisable in such situation to set the shortest possible time for determining the maxi-

mum and minimum value, i.e. half-period). Short time averaging will give more precise diagrams of

changes of parameters over time, and minimums and maximums will be detected and recorded.

Recording with short averaging times is performed mostly during a limited time, primarily due to

rapid growth of data; the aim of such recording is identifying the possible cause of a problem, and

not a long-term analysis.

Recording with a short averaging time may be sufficient to evaluate the performance of the

mains and disturbances in it. However, equally detailed information can probably also be obtained

with longer times (in minutes) but with activated recording of minimum and maximum values and

event detection. An important advantage in this situation that the volume of recorded data is much

smaller which means faster data retrieval and analysis.

On the other hand, the power quality tests are usually made according to the EN 50160. In this

case, the analysis is carried out over a longer period of time (e.g. 7 days), and therefore the chosen

averaging time is also long - 10 minutes.

Please note that there is no single best setting for both, the averaging time and other parameters

or event thresholds. Each mains system is different and so are the goals of the mains tests. There-

fore, the optimal configuration of the analyzer may require several approaches and will also depend

on the experience of the operator.