4.2.4 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.4.2.4.1 ExampleConsider a VT with the following data:132kV 120V3 3EQUATION1937 V1 EN (Equation 33)The following setting should be used: VTprim=132 (value in kV) VTsec=120 (value in V)4.2.4.2 Examples how to connect, configure and set VT inputs for most commonlyused VT connectionsFigure 42 defines the marking of voltage transformer terminals commonly used aroundthe world.A(H1)B(H2)b(X2)a(X1)A(H1)N(H2)n(X2)a(X1)b) c)A(H1)N(H2)dn(X2)da(X1)d)VPri+ +VSeca)ANSI11000175_1_en.vsdANSI11000175 V1 ENFigure 42: Commonly used markings of VT terminalsWhere:a) is the symbol and terminal marking used in this document. Terminals marked with a dot indicatethe primary and secondary winding terminals with the same (positive) polarityb) is the equivalent symbol and terminal marking used by IEC (ANSI) standard for phase-to-groundconnected VTsc) is the equivalent symbol and terminal marking used by IEC (ANSI) standard for open deltaconnected VTsd) is the equivalent symbol and terminal marking used by IEC (ANSI) standard for phase-to-phaseconnected VTsSection 4 1MRK 506 334-UUS AAnalog inputs100Application manual
