4.1.4.2 Function blockGUID-22B2621B-5B78-4C71-97F8-4BD477A50D51 V1 ENFigure 99: Function block4.1.4.3 FunctionalityThe three-phase overcurrent protection DPH3xPDOC is used as one-phase, two-phase or three-phase directional overcurrent and short circuit protection for feeders.DPH3xPDOC starts when the value of the current exceeds the set limit anddirectional criterion is fulfilled. Each phase has its own timer. The operation timecharacteristics for the low stage, DPH3LPDOC, and the high stage, DPH3HPDOC,can be selected to be either definite time (DT) or inverse definite minimum time(IDMT).In the DT mode, the function operates after a predefined operation time and resetswhen the fault current disappears. The IDMT mode provides current-dependenttimer characteristics.The function contains a blocking functionality. It is possible to block functionoutputs, timers or the function itself, if desired.4.1.4.4 Operation principleThe function can be enabled and disabled with the Operation setting. Thecorresponding parameter values are "On" and "Off".The operation of the phase-segregated three-pole tripping mode can be describedusing a module diagram. All the modules in the diagram are explained in the nextsections.1YHT530004D05 D Section 4Protection functions615 series 201Technical Manual
