Non-Directional Overcurrent Protection Phxptoc - ABB RELION 630 Series Applications Manual

1MRS756785 G
3.3.6.9
REM630
Application Manual
GUID-1769FB0F-68DC-47F1-BE9C-AD7D84B6115A V1 EN
Figure 19: Motor negative-sequence overcurrent protection

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.
An operate and start signal from the low stage is used to provide a LED indication on
the LHMI. Separate start and operate signals from both functions are connected to the
disturbance recorder.
Section 3
REM630 variants
53