Unbalance Protection; Negative-Sequence Overcurrent Protection Nsptoc; Identification; Function Block - ABB RELION REX640 Technical Manual

1MRS759142 C
4.4
4.4.1
4.4.1.1
4.4.1.2
4.4.1.3
4.4.1.4
REX640
Technical Manual

Unbalance protection

Negative-sequence overcurrent protection NSPTOC

Identification

Function description
Negative-sequence overcurrent
protection

Function block

GUID-54970174-F441-4070-9375-9B3A52A17FAC V1 EN
Figure 406: Function block

Functionality

The negative-sequence overcurrent protection function NSPTOC is used for
increasing sensitivity to detect single-phase and phase-to-phase faults or unbalanced
loads due to, for example, broken conductors or unsymmetrical feeder voltages.
NSPTOC can also be used for detecting broken conductors.
The function is based on the measurement of the negative sequence current. In a fault
situation, the function starts when the negative sequence current exceeds the set limit.
The operate time characteristics 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.

Analog channel configuration

NSPTOC has one analog group input which must be properly configured.
Protection functions
IEC 61850 IEC 60617
identification identification
NSPTOC I2>M
Section 4
ANSI/IEEE C37.2
device number
46M
735