July 31, 2010 — Schweitzer Engineering Laboratories (SEL) announced the SEL-9220 Fiber-Optic Adapter for SEL-300 Series Relays. The SEL-9220 mounts directly to the EIA-485 port on the relay connector that is normally occupied by a compression terminal block. It converts the EIA-485 port to a dedicated point-to-point fiber-optic link that is compatible with SEL-2812 Fiber-Optic Transceivers With IRIG-B and built-in fiber-optic interfaces on a variety of SEL devices. The SEL-9220 and SEL-2812 use one pair of optical fibers for full-duplex communications of serial data, plus transfer an IRIG-B time signal to coordinate device clocks. SEL-300 Series Relays have two EIA-232 ports and one EIA-485 port on the back for permanent connections.
Many applications require three fiber-optic links. SEL-2812 transceivers convert the EIA-232 ports to fiber-optic links, and the SEL-9220 provides the third link. Other applications include SEL-300 Series Relays in electrical substations that often use one port to communicate with a substation automation system or SCADA, another for remote engineering access, and a third for high-speed relay-to-relay communications for distributed bus protection, main-tie-main-schemes, distribution automation, rapid restoration, or remote teleprotection schemes.
