GE Multilin F60 Feeder Protection System 3-253 HARDWARE 3.2 WIRING3Lightning strikes and ground surge currents can cause large momentary voltage differences between remote ends of thecommunication link. For this reason, surge protection devices are internally provided at both communication ports. An iso-lated power supply with an optocoupled data interface also acts to reduce noise coupling. To ensure maximum reliability, allequipment should have similar transient protection devices installed.Terminate both ends of the RS485 circuit with an impedance as shown below.Figure 3–25: RS485 SERIAL CONNECTIONc) 100BASE-FX FIBER OPTIC PORTSEnsure that the dust covers are installed when the fiber is not in use. Dirty or scratched connectors can lead to highlosses on a fiber link.Observing any fiber transmitter output can injure the eye.The fiber optic communication ports allow for fast and efficient communications between relays at 100 Mbps. Optical fibercan be connected to the relay supporting a wavelength of 1310 nm in multi-mode.The fiber optic port is designed such that the response times do not vary for any core that is 100 μm or less in diameter,62.5 μm for 100 Mbps. For optical power budgeting, splices are required every 1 km for the transmitter/receiver pair. Whensplicing optical fibers, the diameter and numerical aperture of each fiber must be the same.NOTE
