CHAPTER 10: THEORY OF OPERATION
SINGLE-POLE TRIPPING
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL
10-45
10
Table 10-25: Unblocking scheme trip table for two-bit channels
10.5.3.4 Four-bit channels
The TX1, TX2, TX3, TX4, RX1, RX2, RX3, and RX4 operands are used.
0
0
CG, AB, ABG, 3P, Unrecognized
AB, ABG, 3P, Unrecognized
DIR BLOCK TRIP 3P
0
1
AG, BC, BCG
BC, BCG Unrecognized
1
0
BG, CA, CAG
CA, CAG Unrecognized
Remote data
Local data
Bit pattern received
Remote determination
of fault type
Local determination of
fault type
Trip output
RX1
LOG1
RX2
LOG2
1
1
0
0
AG, BC, BCG
AG, AB, ABG CA, CAG, 3P
DCUB TRIP A
0
1
0
0
0
0
1
1
BG, CA, CAG
AG
0
0
0
1
1
1
1
1
CG, AB, ABG, 3P,
unrecognized
AG
0
1
1
1
1
1
0
1
0
1
0
1
0
0
1
1
BG, CA, CAG
BG, AB, ABG BC, BCG, 3P
DCUB TRIP B
0
0
0
1
1
1
1
1
CG, AB, ABG, 3P,
unrecognized
BG
0
1
1
1
1
1
0
1
0
1
0
1
1
1
0
0
AG, BC, BCG
BG
0
1
0
0
1
1
0
0
AG, BC, BCG
CG
DCUB TRIP C
0
1
0
0
0
0
1
1
BG, CA, CAG
CG
0
0
0
1
1
1
1
1
CG, AB, ABG, 3P,
unrecognized
CG, BC, BCG, CA, CAG
0
1
1
1
1
1
0
1
0
1
0
1
1
1
0
0
AG, BC, BCG
BC, BCG, unrecognized
DCUB TRIP 3P
0
1
0
0
0
0
1
1
BG, CA, CAG
CA, CAG, unrecognized
0
0
0
1
1
1
1
1
CG, AB, ABG, 3P,
unrecognized
AB, ABG, 3P, unrecognized
0
1
1
1
1
1
0
1
0
1
0
1
Remote data
Local data
Bit pattern received
Remote determination of fault
type
Local determination of fault
type
Trip output
RX1
RX2