The voltage selection type to be used is set with the parameter CBConfig.If No voltage sel. is set the voltages used will be U-Line1 and U-Bus1. This setting isalso used in the case when external voltage selection is provided. Fuse failuresupervision for the used inputs must also be connected.From the voltage selection part, selected voltages, and functions conditions areconnected to the Synchronizing, Synchrocheck and Energizing check inputs.For the disconnector positions it is advisable to use (NO) a and (NC) b type contactsto supply 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 contactsB1QOPEN-B1QCLD for Bus 1, and B2QOPEN-B2QCLD for Bus 2 to selectbetween bus 1 and bus 2 voltages. If the disconnector connected to bus 1 is closed andthe disconnector connected to bus 2 is opened the bus 1 voltage is used. All othercombinations use the bus 2 voltage. The outputs B1SEL and B2SEL respectivelyindicate the selected Bus voltage.The function checks the fuse-failure signals for bus 1, bus 2 and line voltagetransformers. Inputs UB1OK-UB1FF supervise the MCB for Bus 1 and UB2OK-UB2FF supervises the MCB for Bus 2. ULN1OK and ULN1FF supervises the MCBfor the Line voltage transformer. The inputs fail (FF) or healthy (OK) can alternativelybe used dependent on the available signal. If a VT failure is detected in the selectedvoltage source an output signal USELFAIL is set. This output signal is true if theselected bus or line voltages have a VT failure. This output as well as the function canbe blocked with the input signal BLOCK. The function logic diagram is shown infigure 166.Section 12 1MRK 502 048-UEN AControl332Technical manual
