“Settings” Tab of “Overcurrent” Module, Part 2

In “Time” section, first, the injection time before fault in “PreFault Time” is entered. In tests such as “Directional” where by injecting voltage, “PTs” draw inrush current, by checking “Ramp in Prefault” you can create a “Ramp” voltage and prevent device errors.  Note that checking this option is only possible for “Directional” tests or in conditions determined in “Voltage Output” section.

In “Max Fault Time”, the maximum fault injection time is specified in the form of “Abs” or “Rel” which itself includes three sections. Note that if the time specified in “Max Fault Time” is shorter than time of the “Trip” time of the shot point, result of the evaluation will be wrong.

If you are using “Max Fault Time (Abs)” field, you need to enter a time in terms of seconds for the maximum fault signal injection time (for all points). But, to increase the speed of the test, you can use “Max Fault Time (Rel)”. By checking this option, three other options appear. By entering a number in “Add%ofTnom”, the fault signal injection time in each 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 (1.05) equals the test nominal time which is 10.5 seconds. But in “Add Absolute” field, the fault injection time is entered as a sum of the test point trip nominal time plus the time entered in this field. For points which are in “No Trip” area, it is possible to enter a separate time in “No-Trip Time” field. If you enter the time in these four fields, the software will consider the longest time.

“Post Fault” time is entered in “Post Fault Time”. “Delay After Trigger” is used for specifying the trigger time of the intended key and 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, by selecting “Remove Link” you can enter your desired value instead.

By selecting “Fault Inception” in “Time Reference”, the “Trip” time from the fault injection time is calculated. But, by selecting “Starting”, the “Trip” time is calculated from when the “Pick-up” contact is received from the relay.

In “Load Current (Prefault Current)” section, it is possible to adjust the settings related to “Prefault” phase and current. By selecting “Based on Current” radio button in “Amplitude” section, the “Prefault” current is entered in ampere which is the same for all other test points. But, by selecting “Based on IFault”, the “Prefault” current is entered in fault current which is different for every “Shot” point. You can use “Phase” section for the angle between current and voltage in “Prefault”. By selecting the “Based on Degree” radio button, it is possible to specify the voltage current angle in degrees which is the same for all other test points. But, by selecting “Same as Fault Angle”, the angle between current and voltage in “Prefault” will be the same with “Fault” which is different for every “Shot” point.

In “Other Setting” section, by checking first run "PickUp-DropOff", if you have multiple "PickUp-DropOff" and “Shot Test” points, first, the "PickUp-DropOff" test is performed otherwise “Shot Test” is performed first. By checking “Continue Last State Amplitude”, in "PickUp-DropOff" test, instead of starting from “Pickup End” the decreasing ramp will start from where the relay performed the pick-up”.