CIRCUTOR QNA-P Series - Manual (Page 7)

Page no. 6
3.- ANALYSIS MODES.
The QNA-412 series analyzers have different operating modes depending on
how they are set.
The most important operating functions are:
• Measurement and recording in the memory the main electrical supply quality
parameters (voltages, flicker, harmonics and unbalance).
• Measurement and recording in the memory the main electrical parameters
(voltages, currents, frequency, power, PF ...
• Current measurement for Neutral and Neutral-Earth Voltage.
• Setting a voltage threshold to define different events (dips, interruptions and
overvoltages). There is also the option to set a hysteresis value for all these
thresholds.
• The QNA-412 may be installed in both 3 wire and 4 wire systems. All quality
measurements will be made with reference to Neutral or between phases
depending on the selection.
• The QNA-412 may also be used to measure via voltage and current
transformers
4.- RECORDING IN THE MEMORY (automatically).
The QNA-412 has an internal clock, with date and time, to allow it to
automatically record electrical parameters as well as any incident that may occur.
The storage memory for the QNA-412 has four independent blocks reserved
for each type of file that it records. The following information is found in each of these
files:
• *.STD: where the measured data (voltage, current, frequency,
power, energy, flicker, THD, unbalance) is periodically stored.
• *.EVE: where any incident occurring to the QNA-412 is stored (file
reading, Setup change, deleting from the memory, auxiliary power
supply on/off, battery off...).
• *.EVQ: Quality events file where incidents occurring with the
electricity supply are stored (interruptions, dips, overvoltages...) plus
supplementary information on them (time when the incident
occurred, length, maximum/minimum voltage, average voltage,
voltage prior to the event).
• *.H24: where data is stored for statistical studies on the
development of the harmonics throughout a day.
The QNA-412 has a rotating storage memory. This means that if the memory
is full, new data obtained is stored in place of the oldest recordings. Therefore, if no
data is to be lost, files from the memory must be downloaded before it starts
recording over information that has not yet been downloaded.