Thermal Overload Protection T2Pttr; Non-Directional Overcurrent Protection Phxptoc; Machine Negative-Sequence Overcurrent Protection Mnsptoc - ABB RELION 630 Series Applications Manual

Section 3
REG630 variants
3.2.6.2
3.2.6.3
3.2.6.4
32

Thermal overload protection T2PTTR

The three-phase thermal overload protection function is used for thermal protection of
generators. The function has adjustable temperature limits for tripping, alarm and
reclose inhibit. The applied thermal model uses two time constants and a true RMS
current measuring principle. A set of three phase currents, I3P, is connected to the
inputs.
The thermal overload alarm and trip signals provide a LED indication on the LHMI.
The thermal overload alarm and thermal overload trip are also connected to the
disturbance recorders, as well as to common start and common operate respectively.

Non-directional overcurrent protection PHxPTOC

The three-phase non-directional overcurrent functions are used for non-directional
one-, two- and three-phase stator overcurrent and short-circuit protection with
definite-time or various IDMT characteristic. The stage operation 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 high. A set of three phase neutral side currents, I3P_N, is connected
to the inputs. The low stage can be used for overcurrent protection, and the high stages
protect against short circuit.
A common operate and start signal from the both non-directional overcurrent
functions is connected to an OR-gate to form a combined non-directional overcurrent
operate and start signal which provides a LED indication on the LHMI. Also a
separate start and operate signal from the both overcurrent functions is connected to
the disturbance recorder.

Machine negative-sequence overcurrent protection MNSPTOC

Two instances of negative-sequence overcurrent function are provided for stator
protection against single-phasing, unbalance load or unsymmetrical voltage with DT
or IDMT characteristics. A set of three phase neutral side currents, I3P_N, is
connected to the inputs.
A common operate and start signal from the both negative-sequence overcurrent
functions is connected to an OR-gate to form a combined negative-sequence
overcurrent operate and start signal, which is used for providing a LED indication on
the LHMI. Also a separate start and operate signal from the both MNSPTOC functions
is connected to the disturbance recorder.
1MRS757582 C
REG630
Application Manual