V03399
Protection Trip
CB1/CB2 AR in Progress
CB1 Open
Auto-close CB1
Follower Time
Auto-close CB2
Lockout
Reclaim Time
CB2 Open
Dead Time Shot 1
Figure 136: Autoreclose Sequence for an evolving/permanent fault on a dual CB application
3.4.6
AR TIMING SEQUENCE - PERSISTENT FAULT
The figure below shows the start of a multi-shot AR operating sequence where a single-phase fault is not cleared
by the first AR cycle. The sequence starts in a similar way to that of a transient fault, but in this case the fault is not
transient (it may be permanent, or it may evolve into a fault involving more than one phase). This case shows a
second fault inception occurring before the Reclaim Time has expired. The significant point here is that after the
first trip has occurred, the Autorecloser forces the 2 CBs into three-pole operation and different Dead Timers are
used for the single-phase cycle compared with the three-phase cycle.
V03400
Protection Trip
CB1/CB2 AR 1-ph in
Progress
CB1 Open 1 -ph
Auto-close CB1
Follower Time 1-ph
Auto-close CB2
Dead Time 3-ph
Reclaim Time 1-ph
1-ph 3-ph
CB1/CB2 AR 3-ph in
Progress
CB1 Open 3 -ph
CB2 Open 1 -ph
CB2 Open 3 -ph
Dead Time 1-ph
AR Force CB1 3-ph
AR Force CB2 3-ph
Figure 137: Autoreclose Sequence for a persistent fault on a multishot dual CB application set for single-phase
operation
P446SV Chapter 11 - Autoreclose
P446SV-TM-EN-1 259
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