Ratio Card - Omicron Lab CT Analyzer User Manual

6.7

Ratio Card

The Ratio card is only available if it is enabled in the Select Cards page (Default
Test Settings or Select Cards soft key in the CT-Object card).
The ratio test measures the current ratio of the CT considering the operating
burden (parameter "Burden" in CT-Object card) or the nominal burden
(parameter "VA" in CT-Object card).
The results of the ratio test can be found in 3 pages:
•
•
•
For a better understanding of the test results, the most important settings from
the CT-Object card are shown once again in the upper part of the Ratio card.
Note: Although the test is not performed with the real current, the test results
reflect the current ratio and not the voltage ratio.
Figure 6-16
The Ratio card (refer to Figure 6-16) shows the polarity, the ratio error and
the phase displacement for the primary current and the burden defined in the
CT-Object card.
If the Results with Nom. Burden soft key is pressed, the page shows the
results related to the nominal burden ("VA" parameter in the CT-Object
card). If the Results with Op. Burden soft key is pressed, the page shows
the results related to the operating burden ("Burden" parameter in the
CT-Object card).
The ratio table shows the current ratio error for different currents (200%
down to 1% of the rated current) at different burden values (depending on the
selected standard, see section 6.7.4 on page 122 and 6.7.5 on page 123).
The phase table shows the phase displacement for different currents at
different burden values (depending on the selected standard, see section
6.7.4 on page 122 and 6.7.5 on page 123).
Ratio card
The CT Analyzer Test Cards
119