You should program both the upstream and downstream Autoreclose IEDs with the same number of shots to
lockout and number of instantaneous trips before instantaneous pr
otection is blocked. This will ensure that for a
persistent downstream fault, both Autoreclose IEDs will be on the same sequence count and will block
instantaneous protection at the same time. When sequence co-ordination is disabled, the circuit breaker has to be
tripped to start the dead time, and the sequence count is advanced by one.
When using sequence co-ordination for some applications such as downstream pole-mounted reclosers, it may be
desirable to re-enable instantaneous protection when the recloser has locked out. When the downstream recloser
has locked out there is no need for discrimination. This allows you to have instantaneous, then IDMT, then
instantaneous trips again during an Autoreclose cycle. Instantaneous protection may be blocked or not blocked
for each trip in an Autoreclose cycle using the Trip (n) Main and Trip (n) SEF settings, where n is the number of the
trip in the autoreclose cycle.
7.11 SYSTEM CHECKS FOR FIRST RECLOSE
The SysChk on Shot 1 setting in the SY
STEM CHECKS sub menu of the AUTORECLOSE column is used to enable or
disable system checks for the first reclose attempt in an Autoreclose cycle. This may be preferred when high speed
Autoreclose is applied, to avoid the extra time for a synchronism check. Subsequent reclose attempts in a multi-
shot cycle will, however, still require a synchronism check.
Chapter 13 - Autoreclose P14x
304 P14xEd1-TM-EN-1
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