ABB RER620 Technical Manual page 355

1MAC309294-MB F
RER620
Technical Manual
recloser B operation, 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 Group
Settings after t2 seconds (typically set around 10 seconds after the Sectionalizer is set to
trip). See Figure 187 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. Since the fault is permanent, fault current will flow from the alternate
source. With proper coordination in this direction, the mid-point recloser will trip on
overcurrent (one shot due to its SWOTF mode), isolating the faulted section between
Recloser B and C. This establishes service from S2 to Recloser C. 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 from S2 to recloser B never loses service, and from Recloser
C to the tie-point recloser the load is picked back up. Figure 187 and Table 316 summarize
the events.
0.5 s - 1st reclose
15 s - 2nd reclose
45 s - 3rd reclose and lockout
0 t
Recloser B Recloser C senses loss
Permanent of voltage and chages
Fault Initiates to ALT1 setting
Figure 187: 5-Reclosre Fault 2 scenario Sequence of Events
Table 316: 5-Reclosre Fault 2 scenario Sequence of Events
Time Event or Conditon
t0 Permanent line fault occurs. Sectionalizing recloser trips and locks out causing loss of
voltage at the Midpoint and TiePoint reclosers.
t1 Midpoint recloser declares phases dead, initiates loop control sequence, starts SWOTF
timer. May request ALT thresholds (per settings).
t2 TiePoint recloser declares phases dead, initiates loop control sequence and closes its
breaker. May request ALT thresholds (per settings) before closing breaker.
5-Recloser Fault 3 Scenario
If a permanent fault occurred at location F3, Figure 186, the following sequence occurs;
recloser C proceeds through its reclosing sequence of overcurrent protection (assume 3
operations to lockout). Upon tripping of recloser C, recloser T senses loss of voltage and
after its time delay of t1 seconds, closes onto the permanent fault. Since this fault is
permanent and recloser T has closed into the fault, recloser T does not go through the same
recloser sequence as recloser C just went through, recloser T goes directly to lockout. The
unfaulted portion of the distribution feeder circuit between S1 to recloser C remains in
t1 2 t
Recloser T
changes to ALT1
setting and closes
t1 + 5s
Section 5
Control functions
349