ANDANDANDbus1VoltageORORORVL1FFVL1OKVB1FFVB1OKVB2FFVB2OKBUS2_CLBUS2_OPBUS1_CLBUS1_OPselectedFuseOKBLOCKbus2VoltagebusVoltageAND invalidSelectionB2SELB1SELANDANDAND VSELFAILen05000779_2_ansi.vsdORNOTANSI05000779 V2 ENFigure 166: Logic diagram for the voltage selection function of a single circuit breaker with double busbars12.1.7.8 Voltage selection for a breaker-and-a-half circuit breaker arrangementNote that with breaker-and-a-half schemes three Synchronism check functions must beused for the complete diameter. Below, the scheme for one Bus breaker and the Tiebreaker is described.This voltage selection function uses the binary inputs from the disconnectors and circuitbreakers auxiliary contacts to select the right voltage for the SESRSYN (Synchronism,Synchronizing and Energizing check) function. For the bus circuit breaker one side of thecircuit breaker is connected to the busbar and the other side is connected either to line 1,line 2 or the other busbar depending on the best selection of voltage circuit.Inputs LINE1_OP-LINE1_CL, BUS1_OP-BUS1_CL, BUS2_OP-BUS2_CL,LINE2_OP-LINE2_CL are inputs for the position of the Line disconnectors respectivelythe Bus and Tie breakers. The outputs L1SEL, L2SEL and B2SEL will give indication of1MRK 502 048-UUS A Section 12Control357Technical manual
