GE L90

CHAPTER 10: THEORY OF OPERATION SINGLE-POLE TRIPPING
L90 LINE CURRENT DIFFERENTIAL SYSTEM – INSTRUCTION MANUAL 10-47
10
Table 10-30: Blocking scheme trip table for four-bit channels
Table 10-31: Unblocking scheme trip table for four-bit channels
1 0 0 0 AG BC, BCG Trip Three Phases
0 1 0 0 BG CA, CAG
0 0 1 0 CG AB, ABG
0 0 0 1 MULTI-P Unrecognized
Remote data Local data
Bit pattern received Remote determination of
fault type
Local determination of fault
type
Trip output
RX1 RX2 RX3 RX4
0 0 0 0 Any while the INIT signal
was not established
Trip as for single-bit
channel
1 1 1 0 MULTI-P AG DIR BLOCK TRIP A
10 1 1BG AG
11 0 1CG AG
0 1 1 1 AG AG, AB, ABG, CA, CAG, 3P,
Unrecognized
1 0 1 1 BG BG, AB, ABG, BC, BCG, 3P,
Unrecognized
DIR BLOCK TRIP B
01 1 1AG BG
11 0 1CG BG
11 1 0MULTI-P BG
1 1 0 1 CG CG, BC, BCG, CA, CAG, 3P,
Unrecognized
DIR BLOCK TRIP C
01 1 1AG CG
10 1 1BG CG
11 1 0MULTI-P CG
0 1 1 1 AG BC, BCG DIR BLOCK TRIP 3P
1 0 1 1 BG CA, CAG
1 1 0 1 CG AB, ABG
1 1 1 0 MULTI-P Unrecognized
Remote data Local data
Bit pattern received Remote
determinatio
n of fault
type
Local determination
of fault type
Trip output
RX1 LOG1 RX2 LOG2 RX3 LOG3 RX4 LOG4
00 0000 1 1 MULTI-PAG DCUB TRIP A
00 0000 0 1
00 1100 0 0 BG
00 0100 0 0
00 0011 0 0 CG
00 0001 0 0
1 1 0 0 0 0 0 0 AG AG, AB, ABG, CA, CAG,
3P, unrecognized
01 0000 0 0
Remote data Local data
Bit pattern received Remote
determination of
fault type
Local determination of fault
type
Trip output
RX1 RX2 RX3 RX4