3-12 B30 Bus Differential System GE Multilin3.2 WIRING 3 HARDWARE3.2.5 PROCESS BUS MODULESThe B30 can be ordered with a process bus interface module. This module is designed to interface with the GE MultilinHardFiber system, allowing bidirectional IEC 61850 fiber optic communications with up to eight HardFiber merging units,known as Bricks. The HardFiber system has been designed to integrate seamlessly with the existing UR-series applica-tions, including protection functions, FlexLogic, metering, and communications.The IEC 61850 process bus system offers the following benefits:• Reduces labor associated with design, installation, and testing of protection and control applications using the B30 byreducing the number of individual copper terminations• Integrates seamlessly with existing B30 applications, since the IEC 61850 process bus interface module replaces thetraditional CT/VT modules• Communicates using open standard IEC 61850 messagingFor additional details on the HardFiber system, see GE publication GEK-113658: HardFiber Process Bus System Instruc-tion Manual.3.2.6 CONTACT INPUTS AND OUTPUTSEvery contact input/output module has 24 terminal connections. They are arranged as three terminals per row, with eightrows in total. A given row of three terminals can be used for the outputs of one relay. For example, for form-C relay outputs,the terminals connect to the normally open (NO), normally closed (NC), and common contacts of the relay. For a form-Aoutput, there are options of using current or voltage detection for feature supervision, depending on the module ordered.The terminal configuration for contact inputs is different for the two applications.The contact inputs are grouped with a common return. The B30 has two versions of grouping: four inputs per commonreturn and two inputs per common return. When a contact input/output module is ordered, four inputs per common is used.If the inputs must be isolated per row, then two inputs per common return should be selected (4D module).The tables and diagrams on the following pages illustrate the module types (6A, etc.) and contact arrangements that can beordered for the relay. Since an entire row is used for a single contact output, the name is assigned using the module slotposition and row number. However, since there are two contact inputs per row, these names are assigned by module slotposition, row number, and column position.Some form-A / solid-state relay outputs include circuits to monitor the DC voltage across the output contact when it is open,and the DC current through the output contact when it is closed. Each of the monitors contains a level detector whose out-put is set to logic “On = 1” when the current in the circuit is above the threshold setting. The voltage monitor is set to “On =1” when there is a voltage across open contact (the detector allows a current of about 1 to 2.5 mA), and the current monitoris set to “On = 1” when the current flowing through the closed contact exceeds about 80 to 100 mA. The voltage monitor isintended to check the health of the overall trip circuit, and the current monitor can be used to seal-in the output contact untilan external contact has interrupted current flow. If enabled, the current monitoring can be used as a seal-in signal to ensurethat the form-A contact does not attempt to break the energized inductive coil circuit and weld the output contacts.Block diagrams are shown as follows for form-A and solid-state relay outputs with optional voltage monitor, optional currentmonitor, and with no monitoring. The actual values shown for contact output 1 are the same for all contact outputs. Form-Acontact output with or without a current or voltage monitoring option is not polarity sensitive. The polarity shown in the figureis required for solid-state contact output connection.
