Directional protection of 2 transformers in parallel: suggested alternative settings to avoid incorrect operation (i.e. spurious tripping) of Sepam units



Goals and Symptoms

Standard setting of angle for directionnal protection is in this case is 45° but incorrect operation ( (i.e. spurious tripping) can occur with this setting.

Facts and Changes

Key Words and Phrases:
unexpected trips, directional detection, undetected events, non-detection, unwarranted tripping

Causes and Fixes

Attached document explains which alternative settings can be used to avoid spurious tripping.


  • Last Revised: 13 June 2008 by DRM

    Applies To: Operation of Sepam Protection Relays

    Original Author: DM


    All content © 1992-2008 Schneider Electric

Legacy KB System (APS) Data: RESL191288 V2.0, Originally authored by KBAdPM on 02/27/2008, Last Edited by DaMi on 06/14/2008
Related ranges: Sepam series 80, Sepam series 40, Protection plan