GE Multilin C60 Breaker Protection System 5-1055 SETTINGS 5.4 SYSTEM SETUP55.4.3 SIGNAL SOURCESPATH: SETTINGS 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 letter repre-sents 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” ina particular CT/VT module. See the Introduction to AC Sources section at the beginning of this chapter for details on thisconcept.It is possible to select the sum of all CT combinations. The first channel displayed is the CT to which all others will bereferred. For example, the selection “F1+F5” indicates the sum of each phase from channels “F1” and “F5”, scaled towhichever CT has 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,ratio and nominal secondary voltage. Once the inputs have been specified, the configuration for each source is entered,including specifying which CTs are summed together.User selection of AC parameters for comparator elements:CT/VT modules automatically calculate all current and voltage parameters from the available inputs. Users must select thespecific input parameters to be measured by every element in the relevant settings menu. The internal design of the ele-ment specifies which type of parameter to use and provides a setting for source selection. In elements where the parametermay be either fundamental or RMS magnitude, such as phase time overcurrent, two settings are provided. One settingspecifies the source, the second setting selects between fundamental phasor and RMS.AC input actual values:The calculated parameters associated with the configured voltage and current inputs are displayed in the current and volt-age sections of actual values. Only the phasor quantities associated with the actual AC physical input channels will be dis-played here. All parameters contained within a configured source are displayed in the sources section of the actual values.Disturbance detectors (internal):The disturbance detector (ANSI 50DD) element is a sensitive current disturbance detector that detects any disturbance onthe protected system. The 50DD function is used directly in some elements in the relay, for example VT Fuse Failure detec-tor or Fault Report. It can also be used to supervise current-based elements to prevent maloperation as a result of thewrong settings or external CT wiring problem. A disturbance detector is provided for each source.The 50DD function responds to the changes in magnitude of the sequence currents. The disturbance detector schemelogic is as follows: SOURCE 1SOURCE 1 NAME:SRC 1Range: up to six alphanumeric charactersMESSAGE SOURCE 1 PHASE CT:NoneRange: None, F1,... up to any 6 CTs. Only Phase CTinputs are displayed.MESSAGE SOURCE 1 GROUND CT:NoneRange: None, F1,... up to any 6 CTs. Only Ground CTinputs are displayed.MESSAGE SOURCE 1 PHASE VT:NoneRange: None, F5, M5Only phase voltage inputs are displayed.MESSAGE SOURCE 1 AUX VT:NoneRange: None, F5, M5Only auxiliary voltage inputs are displayed.
