Where:1) shows how to connect single-phase CT input in the IED.2) is TRM where these current inputs are located. It shall be noted that for all these current inputsthe following setting values shall be entered.For connection (a) shown in figure 26:CTprim = 1000 ACTsec = 1ACTWyePoint=ToObjectFor connection (b) shown in figure 26:CTprim = 1000 ACTsec = 1ACTWyePoint=FromObject3) shows the connection made in SMT tool, which connect this CT input to the fourth input channelof the preprocessing function block 4).4) is a Preprocessing block that has the task to digitally filter the connected analog inputs andcalculate values. The calculated values are then available for all built-in protection and controlfunctions within the IED, which are connected to this preprocessing function block.If frequency tracking and compensation is required (this feature is typically required only forIEDs installed in the power plants) then the setting parametersDFTReference shall be setaccordingly.4.2.3 Setting of voltage channelsAs the IED uses primary system quantities the main VT ratios must be known to the IED.This is done by setting the two parameters VTsec and VTprim for each voltage channel.The phase-to-phase value can be used even if each channel is connected to a phase-to-ground voltage from the VT.4.2.3.1 ExampleConsider a VT with the following data:132kV 120V3 3EQUATION1937 V1 EN (Equation 1)The following setting should be used: VTprim=132 (value in kV) VTsec=120 (value in V)4.2.3.2 Examples how to connect, configure and set VT inputs for most commonlyused VT connectionsFigure 27 defines the marking of voltage transformer terminals commonly used aroundthe world.Section 4 1MRK 505 337-UUS -Analog inputs78Application manual
