Omicron Lab CT Analyzer, User Manual

Page: 240 / 254

CT SB2 User Manual
46
Note: Notice that the nominal burdens assigned to the tap combinations are
scaled down from the nominal burden for the full tap combination according to
the ratios! The
MR-Results card will therefore show different results for the tap
combinations when switching between the results display with nominal
burdens and the results display with operating burden , even if identical
values are specified for VA and Burden in the CT-Object card.
Hint:
Once the test is finished, it is possible to simulate the performance of the CT for
other burden values than the nominal burden by changing the "Burden" value in
the
CT-Object card. The CT Analyzer then automatically performs a
recalculation of the results for the new operating burden. Such simulations can
be done at any time after the test is finished if the corresponding test file
containing the measurement results of the CT is loaded in the
CT Analyzer .
Ratio results or excitation results
The measurement results are displayed on two different pages (see Figure 6-4
on page 44). You can toggle these pages using the
Show Excit. or Show Ratio
soft key.
The following table lists the ratio results displayed in the MR-Results card.
The following table lists the excitation results displayed in the MR-Results
card.
Parameter Description
Ipn : Isec (A) This column shows for each tap combination the measured
current ratio I
pn
/ I
sec
.
N This column shows for each tap combination the measured
winding ratio.
Rat. (%) This column shows for each tap combination the measured
ratio error in %.
Pol. (’)
Pol. (°) This column shows for each tap combination the measured
phase error (polarity) in minutes or degrees. Switch the unit
using the
Pol. in Degrees or Pol. in Min. soft key.
Parameter Description
Rct (m
Ω
) Secondary winding resistance.
Vkn (V) Knee point voltage.
Ikn (mA) Knee point current.