GUID-76CCD7FC-6435-476A-93EB-35411E87FC96 V1 EN
Figure 11: Motor negative-sequence overcurrent protection
3.2.6.8 Non-directional overcurrent protection PHxPTOC
The three-phase non-directional overcurrent functions are used for non-directional
one-phase, two-phase and three-phase overcurrent and short-circuit protection with
definite time or various inverse definite minimum time (IDMT) characteristic. The
operation of a stage is based on three measuring principles: DFT, RMS or peak-to-
peak values.
The configuration includes two variants of non-directional overcurrent function
blocks: low and instantaneous. The set of three phase currents, I3P, is connected to
the inputs. The low stage is blocked during motor startup. It is designed for
additional alarming or protection purposes, like supplementing thermal overload
protection. The low stage can be used as overcurrent protection whereas
instantaneous stages give protection in case of short circuit.
1MRS756785 A Section 3
REM630 variants
REM630 33
Application Manual
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