Function Block; Functionality; Operation Principle - ABB RED615 Technical Manual

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4.1.4.2
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615 series
Technical Manual

Function block

GUID-22B2621B-5B78-4C71-97F8-4BD477A50D51 V1 EN
Figure 99:

Function block

Functionality

The 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 and
directional criterion is fulfilled. Each phase has its own timer. The operation time
characteristics 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 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.

Operation principle

The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
The operation of the phase-segregated three-pole tripping mode can be described
using a module diagram. All the modules in the diagram are explained in the next
sections.
Section 4
Protection functions
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