3-34
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
PILOT CHANNEL COMMUNICATIONS
CHAPTER 3: INSTALLATION
3
All of the fiber modules use ST type connectors. For two-terminal applications, each L90 relay requires at least one
communications channel.
3.4.1 Fiber: LED and ELED transmitters
The following figure shows the configuration for the 7A, 7B, 7C, 7H, 7I, and 7J fiber-only modules.
Figure 3-31: LED and ELED fiber modules
3.4.2 Fiber laser transmitters
The following figure shows the configuration for the 72, 73, 7D, and 7K fiber-laser modules.
Figure 3-32: 7x Laser fiber modules
The 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 the
SETTINGS
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. For
connections to higher-order systems, use the 72 to 77 modules or the 2A and 2B modules.