15.4.7.1 Circuit breaker contact travel time GUID-3AF0EE8D-AA8E-4F83-9916-61B5D0D6B05B v12The circuit breaker contact travel time subfunction calculates the breaker contacttravel time for opening and closing operations. The operation of the breaker contacttravel time measurement is described in figure269.Contact traveltimecalculationPOSCLOSEPOSOPENRSTTRVTAlarm limitcheckBLOCKBLKALMTTRVOPTTRVCLTRVTOPALTRVTCLALIEC12000615-2-en.vsdIEC12000615 V2 EN-USFigure 269: Functional module diagram for circuit breaker contact travel timeContact travel time calculationThe contact travel time of the breaker is calculated from the time between the stateof change of auxiliary contacts. The opening travel time is measured between theopening of the POSCLOSE and closing of the POSOPEN auxiliary contacts.Similarly, the closing travel time is measured between the opening of thePOSOPEN and closing of the POSCLOSE auxiliary contacts. A compensationfactor has been added to consider the time difference between auxiliary contactoperation and the actual physical opening of the breaker main contact.tOpent1 t2 t3 tClose t4Main ContactPOSCLOSEPOSOPEN010110tTravelOpen = tOpen + t1 + t2 tTravelClose = tClose + t3 + t4IEC12000616_2_en.vsdIEC12000616 V2 EN-USFigure 270: Travel time calculationThere is a time difference t1 between the start of the main contact opening and theopening of the POSCLOSE auxiliary contact. Similarly, there is a time difference t2between the time when the POSOPEN auxiliary contact opens and the main contactis completely open. Therefore, a correction factor needs to be added to get theactual opening time. This factor is added with the OpenTimeCorr (t1+t2) setting.1MRK 505 394-UEN A Section 15MonitoringLine differential protection RED650 2.2 IEC 545Technical manual
