P12x/EN T/Eb6 - Schneider - error

P12x/EN AP/Eb6Page 34/78Application GuideMiCOM P120/P121/P122/P123The following diagram shows the logic start of CLPExt. CB 52APositionSettingCold load Pick-up52A Actif SelectableIn the menu CLPDigital logic Input = 52A&C.L.P. not in progressSettingCold load Pick-upAuto-detection ActifSelectable in the menu CLP>1Start C.L.P.A edge detection I under 5%to I more than In andless than 200ms.&C.L.P. not in progressP3941ENa12.1 Exemple of application for earth Fault Protection applied to TransformersWhere an earth fault relay is residually connected on the primary side of a delta-startransformer, no time delay is required for co-ordination purposes, due to the presence of thedelta winding. However, a nominal time delay or stabilising resistor is recommended, toensure transient stability during transformer energising.The CLP logic may be used in a similar manner to that previously described for the motorapplication.This method will not provide stability in the event of asymmetric CT saturation (as a result ofan unbalanced fault condition). In this case, use a stabilising resistor.