Toshiba GR200 Series Instruction Manual page 68

Several schemes are provided; examples describing Re-trip, Zone-trip and Transfer-trip
for the removal of faults following the failure of a target circuit breaker are explained on the
next page using the procedures introduced above.
Example of Zone trip
(i)
External fault outside of the bus-bar and circuit-breaker-failure condition on the
Line CB
Incident
Step1 Fault occurrences on the line:
Remote
end
Step2 Operation of Line protection:
Remote
end
Step3 Operation of CBF Re-trip:
Remote
end
Step4 Operation of CBF Zone-trip:
Remote
end
Note: CB11 is connected to bus-bar zone A.
Failure of CB
CB closed
CB open
CBF re-trip
CBF trip
Table 2.2-3 Operation example #1
Trip issuing and Operation
Busbar
Zone A
CB11
CB12
CBC
Busbar
Zone A
CB11
CB12
CBC
Busbar
Zone A
CB11
CB12
CBC
Busbar
Zone A
CB11
CB12
CBC
- 54 -
A fault occurs on the line;
this fault exists outside of
the
Busbar
Zone B
external
CB21
protection zone.
CB22
The target Line CB at the
remote-terminal trips, but
target CB (CB11) fails to
Busbar
Zone B
trip.
CB21
CB22
A CBF re-trip command is
issued to target CB (CB11)
by the CBF protection. If
Busbar
Zone B
target CB (CB11) trips
CB21
successfully using the re-
trip command, then the
CB22
tripping operation of the
CBF protection is complete.
If the target CB (CB11)
fails to trip at Step 3, a CBF
Zone-trip
Busbar
Zone B
issued to all adjacent CBs
CB21
connected to zone A of the
bus-bar protection. Thus,
CB22
the fault is removed by
tripping all adjacent CBs
connected to bus-bar zone
A.
6F2S1931 (0.20)
Comment
bus-bar and thus
to the busbar
command is
Centralized GRB200
(Soft: 030, 031, 032, 033, 034)