Autoreclose Prot'n Menu; Autoreclose Config Menu - Siemens 7SR18 Solkor Manual

7SR18 Description Of Operation
4.2

Autoreclose Prot'n Menu

This menu presents the Overcurrent Protection elements available for each type of Fault i.e. P/F or E/F 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.
4.3

Autoreclose Config Menu

This menu allows the following settings to be made:-
79 Autoreclose Enabled turns ON all AutoReclose Functions.
79 Num Shots
79 Retry Enable
79 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
79 Sequence Fail Timer Sets the time that AutoReclose start can be primed. Where this time expires before all
Minimum LO Delay
Reset LO by Timer
79 Sequence Co-Ord
79 Cold Load Action
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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.
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 DAR 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.
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
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.
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.
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 followed by current switch-
off. 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.
Selects whether whilst Cold Load is active the relay will perform only Delayed Trips.
When set to Off, both Inst and Delayed elements will be active. This setting does not
block Autoreclose for Cold Load trips.
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