9.9 Stub protection STBPTOC IP14515-1 v39.9.1 IdentificationM17108-1 v2Function description IEC 61850identificationIEC 60617identificationANSI/IEEE C37.2device numberStub protection STBPTOC3I>STUBSYMBOL-T V1 EN-US50STB9.9.2 Application M12904-3 v5In a 1½-breaker switchyard the line protection and the busbar protection normallyhave overlap when a connected object is in service. When an object is taken out ofservice it is normally required to keep the diagonal of the 1½-breaker switchyard inoperation. This is done by opening the disconnector to the protected object. Thiswill, however, disable the normal object protection (for example the distanceprotection) of the energized part between the circuit breakers and the opendisconnector.Stub protection STBPTOC is a simple phase overcurrent protection, fed from thetwo current transformer groups feeding the object taken out of service. The stubprotection is only activated when the disconnector of the object is open.STBPTOCenables fast fault clearance of faults at the section between the CTs andthe open disconnector.1MRK 506 369-UEN B Section 9Current protectionLine distance protection REL670 2.2 IEC 511Application manual
