CIRCUTOR QNA500 series - Manual (Page 39)

POWER QUALITY ANALYZER QNA500 8IO
QNA500 8IO Instruction manual 39 / 111
Flicker (PST) X X X
Voltage Unbalance X
Voltage asymmetry X
Current Unbalance X
Current asymmetry X
The variable recording period can be configured by the user.
FLICKER:
• Pst: QNA500 analyzer will record the Flicker value (Pst) obtained during the recording period.
The Plt value is calculated with the PC's analysis software Flicker is defined as the variation of
the RMS value or amplitude of the voltage within a range of less than 10% of the nominal value.
This variation in voltage amplitude produces a fluctuation of the luminous flux in lamps, at the
same time inducing a sensation of visual instability (visual flashing effect).
HARMONICS:
• Harmonic Distortion: QNA500 analyzer measures, calculates and records the mean harmonic
distortion of the voltage and current detected from the analyzed network.
• Individual Harmonics: QNA500 analyzer measures, calculates and records the mean value of
the individual harmonic distortion rate of each voltage and current harmonic from the analyzed
network (up to the 40th harmonic). (Breakdown of each 10-cycle block integrated in a recording
period).
INTERHARMONICS:
QNA500 measure and register voltage and current interhamornics. These are signals introduced in the
power cable with frequencies non-multiple of the fundamental frequency (50 or 60Hz). QNA500 is able
to measure up to interharmonic 50, corresponding to signals with frequency of 2525Hz.
UNBALANCE:
• Voltage unbalance coefficient (Kd): homopolar and direct voltage ratio.
• Voltage asymmetry coefficient (Ka): inverse and direct voltage ratio.