Omicron CT SB2 User Manual page 240

CT SB2 User Manual
Table 9-3: Parameters and settings used or determined during the test (continued)
Parameter Description
Tap in Use The tap combination actually used during operation of the CT (e.g. X1-X4).
Select the tap combination using the soft keys (for example X1-X5, X1-X4). To
select an intertap combination for the tap in use, press the Show Inter Taps soft
key. The MR-Config. card then offers soft keys for the intertap combinations (for
example X2-X4, X3-X4).
For the tap combination selected here, CT Analyzer displays the detailed test
results in the Resistance, Excitation and Ratio cards. The automatic test
assessment in the Assessment card is however always done for the full tap
combination given by the Number of Taps (e.g. for X1-X5 if number of taps = 5).
See sections 9.4 and 9.5 on page 57.
By default, the "Tap in Use" is set to the full tap combination given by the "Number
of Taps".
Taps This column lists all possible tap combinations of the CT (e.g. X1-X5, X1-X4,
X1-X3, ...). The number of available tap combinations depends on the number of
taps specified in the "Number of Taps" field.
When the MR-Config. card is displayed but not in edit mode (i.e., the card's tab is
highlighted as shown in Figure 9-2 on page 50) you can switch the common tap.
Example:
X1 is assumed as the default common tap, X5 as the highest available tap: Press
the Common Tap to X5 soft key to use X5 as common tap instead of X1. The soft
key then changes to Common Tap to X1.
Using the Show Inter Taps soft key you can display the intertap combinations
instead of the tap combinations. If the intertap combinations are displayed, the soft
key changes to Show Taps.
Examples of intertap combinations: X2-X3, X2-X4, X3-X4.
Ipn : Isn (A) Use this column to set the nominal current ratio I
The nominal ratio for the full tap combination (e.g. X1-X5 for a 5-tap CT) is
automatically taken from the CT-Object card and cannot be changed in the
MR-Config. card.
For all other tap combinations, I
always taken from the CT-Object card.
CT Analyzer automatically performs a plausibility check for the ratios entered by
the user. For example, an error message is displayed if the I
is higher than the I
If you selected a predefined multi-ratio scheme in the CT-Object card using the
soft keys (IEEE C57.13 only; see "I-pn" on page 47), CT Analyzer automatically
enters the nominal CT ratios for all tap combinations according to this scheme.
The ratios of the intertap combinations (e.g. X2-X4) are calculated from the tap
combinations and cannot be changed by the user.
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can be changed or entered by the user. I
pn
specified for X1-X4.
pn
/ I for each tap combination.
pn sn
entered for X1-X3
pn
is
sn
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