5-88 B30 Bus Differential System GE Multilin5.4 SYSTEM SETUP 5 SETTINGS55.4.7 BUSPATH: SETTINGS SYSTEM SETUP BUS BUS ZONE 1(2)Two bus differential zones can be configured. The zone is associated with its own bus differential protection element andCT trouble monitoring element.The bus differential zone is defined by providing the names of sources whose currents bound the differential zone (refer tosettings BUS ZONE 1A SOURCE to BUS ZONE 1F SOURCE).The connection status of a circuit with respect to the protected bus is dynamically provided by FlexLogic operands assignedto the BUS ZONE 1A STATUS to BUS ZONE 1F STATUS settings. The selected operand must be ON when the corresponding cir-cuit is connected to the bus. The operands are selected from the contact inputs that reflect positions of particular circuitswitches and/or breakers. If contact discrepancy filtering is needed, accomplish this using appropriate FlexLogic to form aVirtual Output, representing the current circuit status. If a given circuit (feeder) is fixed to the protected bus section and can-not be attached to any other bus section, then use the FlexLogic "ON" operand to represent fixed circuit status.The status signal is meant to exclude a given current from the bus zone if the circuit is connected to a different bus sectionand its non-zero values would upset the current balance causing a spurious differential signal. Therefore, it is not requirednor recommended to use the position of the breaker to control the status signal of a given circuit. If the breaker is opened,the circuit may remain included in the bus differential zone as the zero current values are measured and used when calcu-lating the differential signal. Dynamically excluding or including a given current during the breaker operation can causeundesirable transients and race conditions for the relay algorithm.If a given circuit cannot be connected to any other bus section different than the protected one, the FlexLogic™ constant"On" is recommended for the status signal. BUS ZONE 1BUS ZONE 1A SOURCE:SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6MESSAGE BUS ZONE 1B SOURCE:SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6MESSAGE BUS ZONE 1C SOURCE:SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6MESSAGE BUS ZONE 1D SOURCE:SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6MESSAGE BUS ZONE 1E SOURCE:SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6MESSAGE BUS ZONE 1F SOURCE:SRC 1Range: SRC 1, SRC 2, SRC 3, SRC 4, SRC 5, SRC 6MESSAGE BUS ZONE 1A STATUS:OffRange: FlexLogic™ operandMESSAGE BUS ZONE 1B STATUS:OffRange: FlexLogic™ operandMESSAGE BUS ZONE 1C STATUS:OffRange: FlexLogic™ operandMESSAGE BUS ZONE 1D STATUS:OffRange: FlexLogic™ operandMESSAGE BUS ZONE 1E STATUS:OffRange: FlexLogic™ operandMESSAGE BUS ZONE 1F STATUS:OffRange: FlexLogic™ operand
