“Differential” Room Settings

In this tab you can manage some of the settings related to performing the tests. In “Supply Direction” section, you can specify the injection and fault direction at the two sides of the protective device. By opening “Medium Detail View” window, you can see that on which side the fault point is located and by changing the “Supply Direction” type you can view that changes. Also, in this section it is possible to view the current amount, fault supplement direction etc. in “Fault Inception” section, the angle where the fault occurs is specified and the currents of the both sides are equally shifted. To better understand this, select “Signal View” from the toolbar and check “Voltage group A” from “Setting” and by changing the value of “Angle”, view the voltage and current signal changes. In differential test, if for any reason you wish to activate your voltages, you can use “Voltage Output”.

In “Time” section, first, the injection time before the fault is entered in “PreFault Time”. In “Max Fault Time” the maximum fault injection time is specified in two forms of “Abs” or “Rel” which consist of three parts themselves. About this time note that if in a “Shot” point the “Max Fault Time” is shorter than “Pick up” time, the result of the evaluation is wrong. If you are using the “Max Fault Time(Abs)” field, you need to enter a time in terms of seconds for the maximum fault signal injection time (for all of the points) but to accelerate the test, you can use the “Max Fault Time(Abs)” option.

By checking this option, three other options appear. By entering a number in “Add %of Tnom”, the fault signal injection time in any point, equals the test point nominal time plus a percentage of the nominal time entered in this field. This means that if the test point nominal time is 10 seconds and 5 percent is entered in this field, the maximum fault injection time is 105 percent of the test nominal time which is 10.5 seconds. But in “Add Absolute” field, the fault injection time equals the sum of the nominal time of the test point trip plus the time entered in this field. If all these three fields are filled, the software picks the longest time entered. For points that are located at the “No Trip” zone, it is possible to enter a separate time in “No-Trip Time” field.

In “Post Fault Time”, the injection time after the fault is entered. “Delay after Trigger”, is used to enter the CB trigger time. By right-clicking on the related field and selecting “Go to Linked Value”, you can see that it is linked to “CB Trip Time” and if necessary, you can replace it with your desired value by selecting “Remove Link”. In “Time Reference”, by selecting “Fault Inception”, the “Trip” time is calculated from when the fault is injected. But by selecting “Starting”, the “Trip” is calculated from when the “Pickup” contact is received from the relay. In “Load Current (PreFault Current)” you can specify the settings for the phase and current related to “PreFault”.  In “Amplitude” section, by selecting “Based on Current” radio button, the “PreFault” current is entered in terms of Ampere which is the same for all test points. But by selecting “Based on IFault”, the “PreFault” current is entered according to the fault current which is different for every “Shot” point.

In “Search Setting” section, the settings related to “Search Test” are specified. As mentioned before, a “Search Test” arrives at a conclusion only if one of the three conditions of this section is met. The first condition is “Relative” which means that if the difference between the test point value and the previous point is less than the percentage specified in this field, this very point is the result of the test. The second condition is “Absolute” which means that if the difference between the test point and the previous point is less than the value specified in this field, this very point is the result of the test. The third condition is “Max point number” which means that the test is to be performed as many times as the number of points entered in this field at max and the last point is the result of the test. But if for any reason, the nominal characteristic determined for the relay is not available, you can use “Ignore Nominal Characteristic” section. By doing so, the software ignores the existing characteristic. Then, based on the step entered in “Search Interval”, it adds shots on the “Search” line. For example, a line is drawn in “Search Test” section. Then, 0.5 is entered as the value for “Search Interval” and “Apply to All” is selected. You can see that some points with the same step are added on the “Search” line. By running the test, you can see that the test starts from the lowest point and once one of the three mentioned conditions is met, the test arrives at a result. Also, if necessary, you can ignore this option by selecting “Disable all”.

By selecting “Shot Passed Only Act In Main Zone” in “Other Setting” section, the test is passed only if the relay performance time in the shot point is somewhere in the allowed range of the main zone. This means that if this option is checked and a shot is added in the tolerance zone of the bottom of the characteristic curve and the relay gives a trip, the test fails because after checking this option, the relay performance is accepted only if it is at the upper zone of the characteristic curve.

“Search Passed Only Act in Zone” is for “Search Test” and by checking this option, the “Search Test” is passed only if the relay trip is in the “Tripping” zone of the nominal characteristic curve of the relay. In “Passed Setting” section, by checking “Pass if Get Any Trip” option, regardless of the relay performance time, if the relay operates in the “Tripping” zone, the test passes.

In “Trigger” tab you can specify the desired binary to receive the “Pickup” and “Trip” signals of the relay as well as stopping the current injection. The settings and explanation of this section are exactly the same as mentioned for “Trigger” room and “Sequencer”. In “Binary Output” tab, if it is necessary for the relay to view the conditions of the circuit breaker, it is possible to take any needed voltage to the “Binary Input” through “Binary Output” of the device by voltages of “A”, “B” or “Aux Dc” groups. This tab has three modes "PreFault","Fault", "Post fault" and you can configure each section separately.