Application Guide - NP900 Series
410 (504
)
A996A
closed indication is received and the autorecloser starts to calculate Reclaim time for
Shot1 simultaneously with the arcing time.
6.
Arcing time for the Shot1 is exceeded which means that the fault is not cleared and
the recloser sends open command to the breaker. Recloser enters to the Shot2 state.
7.
Circuit breaker opens and the Dead time calculation for Shot2 starts.
8.
Shot2 Dead time calculation is finished and the recloser sends close command to the
breaker.
9.
Circuit breaker is closed and since fault cleared by the Shot2 given non-energized
time, no pick-ups are detected. Close command is drop off after the breaker closed
indication is received and the autorecloser starts to calculate Reclaim time for Shot2.
10.
Reclaim Time for Shot2 is exceeded and the reclosing cycle is ended. AR running,
Shot2 Running and REQ1 Running signals are reset and Reclaim Time for the
Autorecloser application starts. Difference in between of the autoreclosing and shot
specific reclaim times is that if fault is returning in shot specific reclaim time
autorecloser jumps to next shot. If a fault return after successful cycle and
Autoreclosing reclaim time is running recloser will go directly to final trip state and
lock-out state. This behavior can be controlled with settings of the recloser. Both of
these reclaim times can be set to 0 when they are not needed. Recloser function will
skip all timers set to 0. Also is possible to set the AR Reclaim not to be used after
successful reclosing cycle.
11.
Autoreclosing Reclaim Time is exceeded and Autorecloser is set to Ready state
waiting for next request.
3.6.4.8
A
UTORECLOSING SEQUENCE FROM
S
TART WITH TWO SHOT
,
HIGH
SPEED SUCCEEDS
The Scheme for autoreclosing starter and shots is the same than in the previous
examples with same settings and signals. In this example fault is cleared by the high
speed autoreclosing.
Figure 3.6.4.8-194 Settings for overcurrent reclosing with two shots.
