ABB RER620, Technical Manual

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Section 5
1MAC309294-MB F
Control functions
346 RER620
Technical Manual
Figure 184: 3-Recloser Fault 2 Sequence of Events
Table 314: 3-Recloser Fault 2 Sequence of Events
Loop Schemes can be setup as one-way or two-way systems. One-way systems allow the
tiepoint recloser close when voltage is lost on one side but not the other. This may be
necessary for situations where the one feeder cannot support additional load but can be
picked up by the other feeder. Two-way schemes are more common, and are set to pick up
load in either direction. For two-way schemes, there may be a need for an alternate
protection setting group change for proper coordination. This can be done automatically
based on programmed settings.
5.4.5.2 Five-Recloser Loop Control
The five-recloser system is similar to the three-recloser system except that a normally
closed Midpoint recloser divides the segments between the TiePoint recloser and each
Sectionalizing recloser.
Figure 185 shows the relative location of midpoint reclosers. The
Mid-point recloser differs from Sectionalizing and TiePoint reclosers in that it does not
initiate breaker operations (trip or close) based on phase voltages. Instead, it alters the
RER620's response to overcurrent conditions. Upon a loss of voltage (below dead bus
threshold voltage level) and after the programmed Dead bus time, the Midpoint RER620
will activate have two additional outputs, which include:
• Switch-on-to-fault (SWOTF)
• SET_GROUP_CHANGE
If the status of phases selected is dead, the SET_GROUP_CHANGE is activated if "En Set
Grp chg" setting is TRUE and SWOTF output is activated for time of SWOTF time setting
preventing the recloser from reclosing back into an anticipated fault for a back feed
condition (after the tie-point closes).
Time Event or Conditon
t0 Permanent fault occurs between Sectionalizing and TiePoint reclosers.
t1 Sectionalizing recloser trips and locks out causing loss of voltage at the TiePoint recloser..
t2 TiePoint recloser declares phases dead, initiates loop control sequence and closes its
breaker.
t3 TiePoint recloser senses line fault, trips and locks out.
Permanent
Fault Initiates
Recloser B
Recloser B locks out
Recloser T
changes to ALT1
settings, Closes
then locks out on
one shot due to fault
2 t 0 t t1
45 s - 3rd reclose and lockout
15 s - 2nd reclose
0.5 s - 1st reclose