12.1.7.6 Voltage selectionThe voltage selection module including supervision of included voltage transformerfuses for the different arrangements is a basic part of the SESRSYN (25) function anddetermines the parameters fed to the Synchronizing, Synchrocheck and Energizingcheck functions. This includes the selection of the appropriate Line and Bus voltagesand fuse supervision.The voltage selection type to be used is set with the parameter CBConfig.If No voltage sel. is set the default voltages used will be V-Line1 and V-Bus1. This isalso the case when external voltage selection is provided. Fuse failure supervision forthe used inputs must also be connected.From the voltage selection part, selected voltages, and fuse conditions are connected tothe Synchronizing, Synchronism check and Energizing check inputs.For the disconnector positions it is advisable to use (NO) a and (NC) b type contacts tosupply Disconnector Open and Closed positions but, it is also possible to use aninverter for one of the positions.12.1.7.7 Voltage selection for a single circuit breaker with double busbarsThis function uses the binary input from the disconnectors auxiliary contacts BUS1_OP-BUS1_CL for Bus 1, and BUS2_OP-BUS2_CL for Bus 2 to select between bus 1 andbus 2 voltages. If the disconnector connected to bus 1 is closed and the disconnectorconnected to bus 2 is opened the bus 1 voltage is used. All other combinations use thebus 2 voltage. The outputs B1SEL and B2SEL respectively indicate the selected Busvoltage.The function checks the fuse-failure signals for bus 1, bus 2 and line voltagetransformers. Inputs VB1OK-VB1FF supervise the fuse for Bus 1 and VB2OK-VB2FFsupervises the fuse for Bus 2. VL1OK and VL1FF supervises the fuse for the Linevoltage transformer. The inputs fail (FF) or healthy (OK) can alternatively be useddependent on the available signal. If a fuse-failure is detected in the selected voltagesource an output signal VSELFAIL is set. This output signal is true if the selected busor line voltages have a fuse failure. This output as well as the function can be blockedwith the input signal BLOCK. The function logic diagram is shown in figure 151.Section 12 1MRK 502 043-UUS BControl328Technical Manual
