A070984 V1 EN
Figure 65: Example coordination of numerical multiple-stage over current
protection
5.1.2 Three-phase directional overcurrent protection DPHxPDOC
5.1.2.1 Identification
IEC 61850 identification:
DPHxPDOC
IEC 60617 identification: 3I> ->, 3I>> ->
ANSI/IEEE C37.2 device number: 67-1, 67-2
5.1.2.2 Functionality
The three-phase overcurrent protection DPHxPDOC is used as one-phase, two-phase
or three-phase directional overcurrent and short-circuit protection for feeders.
DPHxPDOC starts when the value of the current exceeds the set limit and directional
criterion is fulfilled. The operate time characteristics for low stage DPHLPDOC and
high stage DPHHPDOC 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 operate time and resets when
the fault current disappears. The IDMT mode provides current-dependent timer
characteristics.
The function contains a blocking functionality. It is possible to block function outputs,
timers or the function itself, if desired.
5.1.2.3 Application
DPHxPDOC is used as short-circuit protection in three-phase distribution or sub
transmission networks operating at 50 or 60 Hz.
Section 5 1MRS756378 D
Protection functions
140 REF615
Application Manual
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