11.1.7.6 Voltage selectionThe voltage selection module including supervision of included voltage transformers forthe different arrangements is a basic part of the SESRSYN (25) function and determinesthe voltages fed to the Synchronizing, Synchrocheck and Energizing check functions.This includes the selection of the appropriate Line and Bus voltages and MCBsupervision.The voltage selection type to be used is set with the parameter CBConfig.If No voltage sel. is set the voltages used will be V-Line1 and V-Bus1. This setting is alsoused in 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 functions conditions are connectedto the 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 an inverterfor one of the positions.11.1.7.7 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 and bus2 voltages. If the disconnector connected to bus 1 is closed and the disconnector connectedto bus 2 is opened the bus 1 voltage is used. All other combinations use the bus 2 voltage.The outputs B1SEL and B2SEL respectively indicate the selected Bus voltage.The function checks the fuse-failure signals for bus 1, bus 2 and line voltage transformers.Inputs VB1OK-VB1FF supervise the MCB for Bus 1 and VB2OK-VB2FF supervises theMCB for Bus 2. VL1OK and VL1FF supervises the MCB for the Line voltagetransformer. The inputs fail (FF) or healthy (OK) can alternatively be used dependent onthe available signal. If a VT failure is detected in the selected voltage source an outputsignal VSELFAIL is set. This output signal is true if the selected bus or line voltages havea VT failure. This output as well as the function can be blocked with the input signalBLOCK. The function logic diagram is shown in figure 167.Section 11 1MRK 506 335-UUS AControl358Technical manual
