4.1.2 Autoreclose Prot'n Menu; 4.1.3 Autoreclose Config Menu - Siemens 7SR224 Description & Operation

4.1.2 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 Auto Reclose Relay. The resultant configuration enables the Auto
Reclose function to correctly apply the required Protection for each shot in a sequence.

4.1.3 AUTORECLOSE CONFIG Menu

This menu allows the following settings to be made:-
79 Autoreclose
79 Num Shots
79 Retry Enable
79 Retry Attempts
79 Retry Interval
79 Reclose Blocked Delay
79 Sequence Fail Timer Sets the time that AR start can be primed. Where this time expires before all
79 Minimum Lockout Delay Sets the time that the Relay's Lockout condition is maintained. After the
79 Reset LO by Timer Set to Enabled this ensures that the Lockout condition is reset when the timer
79 Sequence Co-Ord When set to Enabled the Relay will co-ordinate its sequence and shot count
©2009 Siemens Protection Devices Limited
Enabled turns ON all AutoReclose Functions.
Sets the allowed number of AutoReclose attempts in a sequence.
Enabled configures the relay to perform further attempts to automatically
Close the 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.
Sets the time delay between retry attempts.
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.
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.
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.
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.
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 auto-
reclose 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.
(1) Description of Operation 7SR224
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