CIRCUTOR QNA-P Series - Manual (Page 5)

Page no. 4
2.1.- Basic features.
The QNA-412 quality analyzer is specially designed to analyse electrical
supply quality according to the specifications in the IEC 61000-4-30 standard.
It has 4 x 2V inputs (clamps) as well as the voltage inputs (isolated by
transformers). This means that as well as the supply quality calculations, the QNA-
412 can be used as a system analyzer.
Its outer design in accordance with DIN 43857 makes it ideal for locating in
any meter station cabinet.
Moreover, the large variety of models makes the QNA-412 adaptable to any
situation and any communication mode.
The equipment's internal battery allows it to take measurements in the event of
any loss of voltage (interruption or dip). It is guaranteed that the QNA-412 continues
operating if there is an interruption in the equipment's power supply.
The QNA-412 has three AC voltage inputs that lets it analyse voltage in the
three phases and the frequency of a predetermined system (quality of supply).
The QNA-412 uses a DSP to analyse the quality of electrical supply according
to the IEC 61000-4-30 standard. The DSP analyses all cycles of the three voltage
phases and checks whether any incident has occurred (dip, interruption,
overvoltage). It also calculates harmonics and flicker according to the IEC 61000-4-7
and 61000-4-15 standards respectively.
Thanks to its 2V inputs (2V/5A ratio), the QNA-412 can analyse the main
electrical parameters in the 4 quadrants (Consumption and generation).
The QNA also has a Neutral current input and another to measure Neutral-
Earth voltage. These parameters complete the information that the QNA supplies
when analysing the electrical system.
The QNA-412 has a 4 Mbyte internal memory where the quality parameters,
electrical parameters and incidents are recorded.
The QNA-412 memory has four types of 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 about 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.