105
6
F
2
S
0
8
5
0
start-up. Tripping of the adjacent breakers can be blocked with the scheme switch [BF2].
There are two kinds of mode of the retrip signal to the original breaker RETRIP: the mode in
which RETRIP is controlled by the overcurrent element OCBF, and the direct trip mode in
which RETRIP is not controlled. The retrip mode together with the trip block can be selected
with the scheme switch [BF1].
Figure 2.11.2 shows a sequence diagram of the BFP when a retrip and backtrip are used. If the
breaker trips normally, the OCBF is reset before timer TBF1 or TBF2 is picked up and the BFP
is reset.
If the OCBF continues operating, a retrip command is given to the original breaker after the
setting time of TBF1. Unless the breaker fails, the OCBF is reset by the retrip. The TBF2 is not
picked up and the BFP is reset. This may happen when the BFP is started by mistake and
unnecessary tripping of the original breaker is unavoidable.
If the original breaker fails, retrip has no effect and the OCBF continues operating and the TBF2
is picked up finally. A trip command CBF-TRIP is issued to the adjacent breakers and the BFP is
completed.
Fault
CBF
-
TRIP
TBF2
RETRIP
TBF1
OCBF
Original
breaker
Adjacent
breakers
TRIP
Retrip
Toc
Toc
Tcb
T cb
TBF1
TBF2
Normal trip
Trip
Open
Closed
Start BFP
Open
Open
Closed
Tcb: operating time of the original breaker
Toc: reset time of the overcurrent element OCBF
Figure 2.11.2 Sequence Diagram
www
. ElectricalPartManuals
. com
Summary of Contents for GRL100-701B
Page 329: ... 328 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 339: ... 338 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 351: ... 350 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 381: ... 380 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 413: ... 412 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 417: ... 416 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 453: ... 452 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 457: ... 456 6 F 2 S 0 8 5 0 w w w E l e c t r i c a l P a r t M a n u a l s c o m ...
Page 473: ...w w w E l e c t r i c a l P a r t M a n u a l s c o m ...