With correct setting of the primary CT direction, CTStarPoint set to FromObject orToObject, a positive quantities always flowing towards the protected object and adirection defined as Forward always is looking towards the protected object. Thefollowing examples show the principle.4.2.2.1 Example 1 SEMOD55055-23 v6Two IEDs used for protection of two objects.TransformerprotectionTransformerLineLineSetting of current input:Set parameterCTStarPoint withTransformer asreference object.Correct setting is"ToObject"ForwardReverseDefinition of directionfor directional functionsLine protectionSetting of current input:Set parameterCTStarPoint withTransformer asreference object.Correct setting is"ToObject"Setting of current input:Set parameterCTStarPoint withLine asreference object.Correct setting is"FromObject"IEC05000753=IEC05000753=1=en=Original[1].vsdIsIsIp Ip IpIED IEDIEC05000753 V2 EN-USFigure 7: Example how to set CTStarPoint parameters in the IEDFigure 7 shows the normal case where the objects have their own CTs. The settingsfor CT direction shall be done according to the figure. To protect the line, directionof the directional functions of the line protection shall be set to Forward. Thismeans that the protection is looking towards the line.4.2.2.2 Example 2 SEMOD55055-29 v7Two IEDs used for protection of two objects and sharing a CT.1MRK 511 401-UEN A Section 4Analog inputsBay control REC670 2.2 IEC 61Application manual
