Section 5 1MAC309294-MB F
Control functions
348 RER620
Technical Manual
of voltage after the first circuit breaker operation, and if the voltage does not return for the
livebus timer setting, it will automatically trip after t1 seconds (see Figure 186), isolating
the faulted zone on the source side of the recloser.
The Midpoint recloser C senses the same loss of voltage, and if the voltage does not return
for the livebus timer setting will request the RER620 to start its SWOTF timer and, if
programmed, to use new changed group settings after t2 seconds (typically set around 10
seconds after the Sectionalizer is set to lockout).
The tie-point recloser T at the same instant will recognize a loss of 3-phase voltage on the
S1 side of its recloser PTs. After a delay time of t3 seconds from the initial fault at S1 the
tie-point recloser T will close, and if programmed, switch to New Group settings. This
establishes service from S2, recloser A and through the tie-point recloser T to the faulted
sectionalizing recloser B. The TiePoint recloser is typically set to declare its phase
voltages dead sometime after the Midpoint recloser has started its SWOTF timer and
before the SWOTF timer expires.
The unfaulted portion of the distribution feeder circuit between recloser B and recloser T
is picked back up. Figure 186 and Table 315 summarize the events.
Figure 186: 5-Recloser Fault 1 scenario Sequence of Events
Table 315: 5-Recloser Fault 1 scenario Sequence of Events
5-Recloser Fault 2 Scenario
In a 5-recloser loop control scheme, Figure 182, if there is a permanent fault between the
sectionalizing recloser B and the midpoint recloser C at F2, recloser B will recognize the
fault and go through its reclosing shots to lockout (assuming proper coordination with the
circuit breaker at Source 1). Recloser C will recognize a loss of voltage after the first
Time Event or Conditon
t0 Permanent line fault occurs Source breaker trips and locks out causing loss of voltage at
the Sectionalizing, Midpoint and TiePoint reclosers.
t1 Sectionalizing recloser declares phases dead, initiates loop control sequence, trips and
locks out its breaker.
t2 Midpoint recloser declares phases dead, initiates loop control sequence, starts SWOTF
timer and requests ALT thresholds (per settings)
t3 TiePoint recloser declares phases dead, initiates loop control sequence and closes its
breaker. May request ALT thresholds (per settings) before closing breaker.
S1
Permanent
Fault Initiates
Recloser B trips on
Loss of Voltage
Recloser C changes to
ALT1 setting
Recloser T
changes to ALT1
setting and closes
t2 + 5s
t0 t3t2t1
45 s - 3rd reclose and lockout
15 s - 2nd reclose
0.5 s - 1st reclose
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