Figure 5.10: Sync-Check Supervised Reclose Sequence
Referring to Figure 5.10 at t = 0, a nonpermanent phase-ground fault occurs within the relay
Zone 1 reach. The relay detects the fault and asserts the TRIP outputs, fulfilling the first re-
quirement to initiate the reclosing sequence. Because the Z1G Zone 1 ground distance
element is set in the Mask for Reclose Initiate, reclosure is initiated.
In response to the relay TRIP signal, the line breaker opens. This causes the RI bit to
deassert because the Z1P element drops out. When the breaker opens, the breaker auxiliary
contact also opens, deasserting the relay 52A input.
The relay TDUR setting of nine cycles causes the TRIP to remain asserted until cycle eleven.
No reclose cancel condition occurred, and the other three initiating conditions were fulfilled,
so the 79OI timer starts when TRIP drops out.
When the line breaker opens, normal bus voltages are restored. In cycle six the 59S element
asserts, indicating that VS is above the 59VHI setting. The bus is live for reclosing purposes.
In cycle 60, remote breaker has reclosed, the line is reenergized, and the 59P element asserts.
The line is live for reclosing purposes. The magnitude of the difference voltages falls below
the relay 25DV setting, fulfilling the voltage condition requirements for the sync-check
function. The 25T timer starts. In cycle 360, the 25T timer expires, sync-check conditions
have been fulfilled. The relay asserts the SSC bit, and the relay A2 contact closes.
In cycle 361, the 79OI timer expires. The relay issues the CLOSE signal. Because the A2
contact (wired in series with the CLOSE contact) is also closed, the breaker close coil is
energized and the breaker recloses. The relay shot counter (not shown) advances to one and
the 52A input is asserted by closure of the breaker auxiliary contact.
Date Code 920508
Applications
SEL-221F, -1 Instruction Manual
5-41
Summary of Contents for SEL-221F
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Page 110: ...Example Event Report 2 4 12 Event Reporting SEL 221F 1 Instruction Manual Date Code 930830 ...
Page 158: ...SETTINGS SHEET FOR SEL 221F RELAY PAGE 2 OF 6 DATE Date Code 921110 ...
Page 160: ...SETTINGS SHEET PAGE 4 OF 6 FOR SEL 221F RELAY DATE Date Code 930601 ...
Page 161: ...SETTINGS SHEET PAGE 5 OF 6 FOR SEL 221F RELAY DATE Date Code 961208 ...
Page 229: ...SEL 200 Series Relay Main Board Troubleshooting Test Points and Jumper Locations ...