Autoreclose Prot'n Menu; Autoreclose Config Menu - Siemens 7SR224 Technical Manual

4.1.3 AUTORECLOSE PROT'N Menu

This menu presents the Overcurrent Protection elements available for each type of Fault i.e. P/F, E/F or SEF and
allows the user to select those that are to be applied as Inst trips; those that are to be applied as Delayed Trips;
and those that are to be applied as HS Trips (HighSet), as required by the selected sequence. There is no
corresponding setting for External as the External protection type is not normally controlled by the Autoreclose
Relay. The resultant configuration enables the Autoreclose function to correctly apply the required Protection for
each shot in a sequence.

4.1.4 AUTORECLOSE CONFIG Menu

This menu allows the following settings to be made:-
79 Autoreclose Enabled turns ON all Autoreclose Functions.
Sets the allowed number of Autoreclose attempts in a sequence.
79 Num Shots
Enabled configures the relay to perform further attempts to automatically Close the
79 Retry Enable
Circuit Breaker where the CB has initially failed to close in response to a Close
command. If the first attempt fails the relay will wait for the 79 Retry Interval to expire
then attempt to Close the CB again.
Sets the maximum number of retry attempts.
79 Retry Attempts
Sets the time delay between retry attempts.
79 Retry Interval
79 Reclose Blocked Delay If the CB is not ready to receive a Close command or if system conditions are such
that the CB should not be closed immediately e.g. a close-spring is not charged, then
a Binary input mapped to Reclose Block can be raised and the Close pulse will not be
issued but will be held-back. The 79 Reclose Blocked Delay sets the time Reclose
Block is allowed to be raised, if this time delay expires the Relay will go to Lockout. If
Reclose Block is cleared, before this time expires, then the CB Close pulse will be
issued at that point in time. Dead Time + Reclose Blocked Delay = Lockout.
79 Sequence Fail Timer Sets the time that AR start can be primed. Where this time expires before all the AR
start signals are not received i.e. the CB has opened, protection pickups have reset
and the trip relay has reset, the Relay goes to Lockout.
79 Minimum Lockout Delay Sets the time that the Relay's Lockout condition is maintained. After the last allowed
Trip operation in a specific sequence the Circuit Breaker will be left locked-out in the
open position and can only be closed by manual or remote SCADA operation. The 79
Minimum Lockout Delay timer can be set to delay a too-fast manual close after
lockout, this prevents an operator from manually closing onto the same fault too
quickly and thus performing multiple sequences and possibly burning-out Plant.
79 Reset LO by Timer Set to Enabled this ensures that the Lockout condition is reset when the timer expires,
Lockout indication will be cleared; otherwise, set to Disabled, the Lockout condition will
be maintained until the CB is Closed by a Close command.
79 Sequence Co-Ord When set to Enabled the Relay will co-ordinate its sequence and shot count such that it
automatically keeps in step with downstream devices as they advance through their
sequence. The Relay detects that a pickup has operated but has dropped-off before its
associated time delay has expired, it then increments its Shot count and advances to
the next stage of the autoreclose sequence without issuing a trip, this is repeated as
long as the fault is being cleared by the downstream device such that the Relay moves
through the sequence bypassing the INST Trips and moving on to the Delayed Trip to
maintain Grading margins.
79 Cold Load Action Set to Delayed will inhibit all instantaneous protection elements when Cold Load settings
are being used.
79 Live Line Checking will set such that it will stop the autoreclose sequence before the Deadtime is started if
neither the line nor bus voltages become dead following the trip. This can be used as a
check that the remote end circuit breaker is tripped before proceeding with the
sequence on a ring connected system. If this check is not required, the 79 Live Line
Check setting should be set to disabled.
©2010 Siemens Protection Devices Limited
7SR224 Argus Description of Operation
Chapter 1 Page 42 of 70