ABB RELION REX640 - 5.11 Communication logic for residual overcurrent RESCPSCH (ANSI 85 67 G;N SCHLGC); 5.11.1 Identification; 5.11.2 Function block; 5.11.3 Functionality

5.10.9 Technical data
Table 1188: DSOCPSCH Technical data
Characteristic Value
Operate time accuracy ±1.0 % of the set value or ±20 ms
5.11 Communication logic for residual overcurrent
RESCPSCH (ANSI 85 67G/N SCHLGC)
5.11.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Communication logic for residual
overcurrent
RESCPSCH CLN 85 67G/N
SCHLGC
5.11.2 Function block
Figure 709: Function block
5.11.3 Functionality
The communication logic for residual overcurrent function RESCPSCH is used to
achieve instantaneous fault clearing independent of the fault location on the
protected feeder. There are four available communication scheme types.
• Direct underreaching transfer trip DUTT
• Permissive underreaching transfer trip PUTT
• Permissive overreaching transfer trip POTT
• Directional comparison blocking scheme DCB
The directional comparison unblocking scheme DCUB can also be provided
by complementing the permissive schemes with an additional logic called the
unblocking function, which is also included in RESCPSCH.
If the permissive overreaching scheme is used, some of the power system
conditions require additional special logic circuits, such as the current reversal and
weak-end infeed logic for residual overcurrent function RCRWPSCH.
1MRS759142 F
Protection related functions
REX640
Technical Manual
1251