GE L90

CHAPTER 10: THEORY OF OPERATION SINGLE-POLE TRIPPING
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 10-43
10
The action output is generated per the following tables.
Table 10-17: Permissive scheme trip table for one-bit channels
Table 10-18: Blocking scheme trip table for one-bit channels
Table 10-19: Unblocking scheme trip table for one-bit channels
The scheme initiates a three-phase trip if the phase selector fails to recognize the fault type or after the AR FORCE 3P TRIP
operand is asserted.
10.5.3.3 Two-bit channels
The TX1, TX2, RX1, and RX2 operands are used and fault data is coded per the following tables.
Table 10-20: Permissive scheme transmit codes for two-bit channels
Remote data Local data
Bit pattern
received
Remote
determination of
fault type
Local determination of fault type Trip output
RX1
1 Any AG Fault Trip Phase A (A+N/G)
1 Any BG Fault Trip Phase B (B+N/G)
1 Any CG Fault Trip Phase C (C+N/G)
1 Any AB, ABG, BC, BCG, CA, CAG, 3P,
Unrecognized
Trip Three Phases (per local selection,
unrecognized and 3P=A+B+C+N/G)
Remote data Local data
Bit pattern
received
Remote
determination of
fault type
Local determination of fault type Trip output
RX1
0 Any AG Fault Trip Phase A
0 Any BG Fault Trip Phase B
0 Any CG Fault Trip Phase C
0 Any AB, ABG, BC, BCG, CA, CAG, 3P,
Unrecognized
Trip Three Phases
Remote data Local data
Bit pattern received Remote
determination of
fault type
Local determination of fault type Trip output
RX1 LOG1
0 or 1 1 Any AG Fault DCUB Trip A
0 or 1 1 Any BG Fault DCUB Trip B
0 or 1 1 Any CG Fault DCUB Trip C
0 or 1 1 Any AB, ABG, BC, BCG, CA, CAG, 3P,
Unrecognized
DCUB Trip 3P
Phase selector determination of
fault type
Bit pattern transmitted
TX1 TX2
AG, BC, BCG 1 0
BG, CA, CAG 0 1
CG, AB, ABG, 3P, Unrecognized 1 1