Distance protection relay Schweitzer Engineering Laboratories

Select the SEL-321 Relay for complete distance protection including single-pole tripping and series-compensated lines.

Apply the SEL-321 Relay for primary and/or backup single-or three-pole trip transmission line protection,including series-compensated lines.Use the advanced single-pole tripping logic with phase selection, open-pole interval protection,and phase discordance logic with three-pole trip to protect against excessive single-pole-open events. Select the load-encroachment feature to prevent operation of three-phase elements under high load conditions. Use the time-overcurrent elements to provide current-dependent, time-delayed fault detection along the protected line and backup protection for remote terminals. SEL SEL-321 has six settings groups for maximum protection scheme flexibility, allow application with bus-tie breakers or for remote system reconfiguration.

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