5-128 L60 LINE PHASE COMPARISON SYSTEM – INSTRUCTION MANUALSYSTEM SETUP CHAPTER 5: SETTINGS55.4.3 Signal sourcesSETTINGS SYSTEM SETUP SIGNAL SOURCES SOURCE 1(4)Identical menus are available for each source. The "SRC 1" text can be replaced by with a user-defined name appropriatefor the associated source.The first letter in the source identifier represents the module slot position. The number directly following this letterrepresents either the first bank of four channels (1, 2, 3, 4) called “1” or the second bank of four channels (5, 6, 7, 8) called“5” in a particular CT/VT module. See the Introduction to AC Sources section at the beginning of this chapter for details.It is possible to select the sum of all CT combinations. The first channel displayed is the CT to which all others are referred.For example, the selection “F1+F5” indicates the sum of each phase from channels “F1” and “F5,” scaled to whichever CThas the higher ratio. Selecting “None” hides the associated actual values.The approach used to configure the AC sources consists of several steps; first step is to specify the information about eachCT and VT input. For CT inputs, this is the nominal primary and secondary current. For VTs, this is the connection type, ratioand nominal secondary voltage. Once the inputs have been specified, the configuration for each source is entered,including specifying which CTs are summed together.Figure 5-56: Source configuration for phase comparisonWhen voltage is supplied to the relay through a VT, it is advisable to assign a source configured with a phase VTvoltage (source 3 or 4) to track system frequency from voltage. Assign source 1 to track frequency from current. SOURCE 1 SOURCE 1 NAME:SRC 1Range: up to 20 alphanumeric characters SOURCE 1 PHASE CT:NoneRange: None, F1,... up to any 6 CTs. Only Phase CTinputs are displayed. SOURCE 1 GROUND CT:NoneRange: None, F1,... up to any 6 CTs. Only Ground CTinputs are displayed. SOURCE 1 PHASE VT:NoneRange: None, L5Only phase voltage inputs are displayed SOURCE 1 AUX VT:NoneRange: None, L5Only auxiliary voltage inputs are displayedFunction CT/VT module 1 (type 8P) CT/VT module 2 (type 8F)SRC 1 SRC 2 SRC 3 SRC 4Phase current F1 to F3 CT channels (usedfor 87PC first current andBreaker Failure 1)Not available L1 to L3 CT channels (usedfor 87PC second currentand Breaker Failure 2). Thissource is configurable onlyif a second CT/VT module isordered.Sum of F1:F3 and L1:L3(used for distance andovercurrent)Ground current F1 (Ground overcurrent) Not available --- ---Phase voltage Not available Not available --- Three-phase line VT fordistance and synchrocheckAuxiliary voltage Not available Not available Single-phase bus VT forsynchrocheck---When two CTs are connected and configured with these settings, it is imperative that the CT rated secondarycurrent is identical for both CTs (that is, both CTs are 1 A rated or both CTs are 5 A rated).
