Ar Timing Sequence - Persistent Fault; Figure 136: Autoreclose Sequence For An Evolving/Permanent Fault On A Dual Cb Application; Figure 137: Autoreclose Sequence For A Persistent Fault On A Multishot Dual Cb Application Set - GE MiCOM P40 Technical Manual

P446SV
Protection Trip
CB1/CB2 AR in Progress
CB1 Open
CB2 Open
Dead Time Shot 1
Auto -close CB1
Follower Time
Auto -close CB2
Reclaim Time
Lockout
V03399

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.
Protection Trip
CB1/CB2 AR 1 -ph in
Progress
CB1/CB2 AR 3-ph in
Progress
CB1 Open 1-ph
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
Auto -close CB1
Follower Time 1 -ph
Auto -close CB2
Reclaim Time 1 -ph
Dead Time 3 -ph
V03400
Figure 137: Autoreclose Sequence for a persistent fault on a multishot dual CB application set for single-phase
operation
P446SV-TM-EN-1
1-ph
Chapter 11 - Autoreclose
3-ph
259