CPU communication processor PFSK151

CPU communication processor PFSK151

CPU communication processor PFSK151

I3PW2CT1: Phase currents for winding 2 first current transformer set. Used for autotransformers. I3PW2CT2: Phase currents for winding 2 second current transformer set for multibreaker arrangements. Used when protecting an autotransformer. When not required, configure input to “GRP-OFF”. Recommendation for Binary input signals Refer to the pre-configured configurations for details. BLOCK: The input will block the operation of the function. Can be used, for example, to block for a limited time the operation during special service conditions. Recommendation for output signals Refer to pre-configured configurations for details.

START: The start output indicates that Idiff is in the operate region of the characteristic. TRIP: The trip output is activated when all operating criteria are fulfilled. DIROK: The output is activated when the directional criteria has been fulfilled. BLK2H: The output is activated when the function is blocked due to a too high level of second harmonic. 6.2.2.2 Settings The parameters for the restricted earth-fault protection, low impedance function REFPDIF are set via the local HMI or PCM600.

Common base IED values for primary current (IBase), primary voltage (UBase) and primary power (SBase) are set in a Global base values for settings function GBASVAL. GlobalBaseSel: It is used to select a GBASVAL function for reference of base values. Operation: The operation of REFPDIF can be switched On/Off. IdMin: The setting gives the minimum operation value. The setting is in percent of the IBase value of the chosen GlobalBaseSel. The neutral current must always be larger than half of this value. A normal setting is 30% of power transformer-winding rated current for a solidly earthed winding.

CTFactorPri1: A factor to allow a sensitive function also at multi-breaker arrangement where the rating in the bay is much higher than the rated current of the transformer winding. The stabilizing can then be high so an unnecessary high fault level can be required. The setting is normally 1.0 but in multi-breaker arrangement the setting shall be CT primary rating/IBase.