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Functions
2.11 Automatic Reclosure Function (optional) 79
If the fault has not been eliminated (unsuccessful reclosure), the short-circuit protection initiates a final trip
following a protection stage active without reclosure. Any fault during the restraint time leads to a final trip.
After unsuccessful reclosure (final tripping) the automatic reclosure is blocked dynamically (see also margin
heading "Reclose Block, above").
The sequence above applies for single reclosure cycles. 7SD80 allow 2 reclosing cycles.
Multiple Automatic Reclosing Attempts
If a short circuit still exists after a reclosing attempt, one more reclosing attempt can be made.
The two reclosing cycles are independent of each other. Each has separate action and dead times and can be
blocked separately via binary inputs.
The sequence is basically the same as described above. However, if the first reclosure attempt was unsuc-
cessful, the reclosure function is not blocked, but instead the second reclose cycle is started. The appropriate
dead time starts with the reset of the trip command or opening of the circuit breaker (pole) (auxiliary contact
criterion). The circuit breaker receives a new close command after expiry of the dead time. At the same time
the restraint time is started.
The restraint time is reset with each new trip command after reclosure and is started again with the next close
command until the set maximum number of permissible automatic reclosing cycles has been reached.
If one of the two reclosing attempts is successful, i.e. the fault disappeared after reclosing, the blocking time
expires and the automatic reclosing system is reset. The fault is terminated.
If no cycle is successful, the short-circuit protection initiates a final trip after the last permissible reclosing,
following the grading time valid without reclosing. The automatic reclosing function is blocked dynamically
(see also above under margin heading "Blocking the Reclosing Function").
Handling of Evolving Faults
If reclose cycles are executed in the power system, particular attention must be paid to evolving faults.
Sequential faults are faults which occur during the dead time after clearance of the first fault.
To detect an evolving fault, you can select either the trip command of a protection function during the dead
time or every further pickup as the criterion for an evolving fault.
It is possible to select the desired response of the internal automatic recloser following the detection of a
sequential fault.
•
EV. FLT. MODE Stops 79:
The reclosure is blocked as soon as an evolving fault is detected. There are no further reclosure attempts;
the automatic reclosure is blocked dynamically (see also margin heading "Blocking reclosure", above).
•
EV. FLT. MODE starts 3p AR:
The separately settable dead time for sequential faults starts with the clearance of the sequential fault;
after the dead time the circuit breaker receives a close command.
If reclosing is blocked due to an evolving fault without the protection device issuing a trip command (e.g. in
the case of evolving fault detection with pickup), the device can send a trip command (intertrip).
Intertrip
The intertrip of the device acts immediately once the circuit-breaker auxiliary contacts signal an implausible
circuit-breaker position.
The device trips via its tripping logic (Section
external devices (Section
Trip and Transmission of Binary
Connecting an External Automatic Recloser
The interaction of the device with an external automatic recloser can be controlled via binary outputs:
501
Relay PICKUP
511
Relay TRIP
134
2.16.2 Tripping Logic for the Entire
2.10 Direct Local Trip
or the reception of a remote trip (Section
Information) act immediately on the tripping logic of the device.
Device). Trip commands from
Start of protection device, general (if required by
external recloser device.
Protection device trip.
E50417-G1100-C474-A2, Edition 02.2018
2.13 Direct Remote
SIPROTEC 4, 7SD80, Manual
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