CIRCUTOR QNA500 series - Manual (Page 40)

POWER QUALITY ANALYZER QNA500 8IO
QNA500 8IO Instruction manual 40 / 111
• Current asymmetry coefficient (Kd): homopolar and direct current ratio.
• Current unbalance coefficient (Ka): inverse and direct current ratio.
K FACTOR:
K Factor is a transformer power reduction factor. The losses generated by harmonics are taken into
account when calculating the K Factor.
It is always higher than the unit in installations with non-linear loads.
e: represents the transformer's copper loss and iron loss ratio. This value can be obtained from the
transformer test data or, alternatively, an approximate value of 0.3 can be used.
q: exponent with a value between 1.7 and 1.8.
CREST FACTOR:
The Crest Factor is equal to the amplitude of the wave shape peak divided by the RMS value. The
crest factor is calculated to provide the analyst with a quick idea of the impact on the wave shape. The
impact is constantly associated with the wear of the roller bearing, cavitation and wear of the gear
cogs, etc.
The crest factor is an important measurement associated to the status of the machine and it analyses
the wave shape, which would not be visible with the calculation of the harmonic distortion rate alone.