Introducing “Test View” Window in “Differential” Room, Part 2

After performing “Shot Test” and “Check Test” in “Differential” room, it is necessary to perform “Search Test”. The purpose of this test is to find the characteristic curve line. To perform a “Search Test”, first some lines named search line should be drawn in different parts of the vector. The method for drawing these lines is the same as the one explained for check line. To draw this line, first the start point of this line is specified in “Search Line” section, “Origin” section. In “Idiff”, “I bias” and “Angle” fields, the origin differential current 2In, the origin bias current 3In and search line angle -30 degrees are entered respectively. The length of the check line 3In is entered in the cell of “Length” section. Then, click on “Add” option to add the check line to “Check Test” test lines table.

Another method for drawing the search line is to hold down left-click and “Ctrl” key on “Differential Characteristic” window and then move the cursor in the desired direction on the characteristic curve. You can see that the information of the drawn Search Line is displayed in “Search Test” lines table. After drawing the search line, the software evaluates the crossing place of search line and tolerance lines as “Shot” test in accordance with the performance of the relay. By performing the test, the software interpolates the characteristic curve by testing some points on the search line to find the exact location of the characteristic curve. “Ignore” field in “Search Interval” section is used when you wish to ignore the characteristic curve specified for the search line.

By entering a number in this section, some points are added on the “Search” line with the entered number as their distance. For example, by entering 0.4 in this field, you can see that there are points added on the “Search Line” with as much as 0.4 of distance. If the test is performed, the points added on the “Search Test” are tested one after the other so that the exact location of the relay is specified. This option is used when there is no characteristic curve for the test or the current characteristics seem to be wrong. If you want to do this for all drawn test lines, you can use the “Setting” tab in “Ignore Nominal Characteristic” section. To do so, by entering the value of “Search Interval” and selecting “Apply to all” option, you can apply this settings to all test lines and find the relay characteristic.

“Stability” test is performed in this tab. In “Stability” test, for zero “I diff” differential current, for every “I bias” the relay must not perform a trip. If you hold down the “Ctrl” key and click on the characteristic curve, you can see that the shot points are located at the bottom of the characteristic curve and on the zero differential current line. In fact, in “Shot Test” you can select different bias currents by zero differential current and perform a stability test. The other explanations for this page are the same as those for “Shot Test” tab and you can watch the video related to that section.