CHAPTER 3: INSTALLATION PILOT CHANNEL COMMUNICATIONSL30 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 3-313All of the fiber modules use ST type connectors. For two-terminal applications, each L30 relay requires at least onecommunications channel.3.4.1 Fiber: LED and ELED transmittersThe following figure shows the configuration for the 7A, 7B, 7C, 7H, 7I, and 7J fiber-only modules.Figure 3-28: LED and ELED fiber modules3.4.2 Fiber laser transmittersThe following figure shows the configuration for the 72, 73, 7D, and 7K fiber-laser modules.Figure 3-29: 7x Laser fiber modulesThe following figure shows configuration for the 2I and 2J fiber-laser modules.The current differential function must be “Enabled” for the communications module to properly operate. See theSETTINGS GROUPED ELEMENTS LINE DIFFERENTIAL CURRENT DIFFERENTIAL menu.The fiber optic modules (7A to 7W) are designed for back-to-back connections of UR-series relays only. Forconnections to higher-order systems, use the 72 to 77 modules or the 2A and 2B modules.
