Siemens siprotec 7SD5 User Manual page 291

Sequence of a If the automatic reclosure function is ready, the fault protection trips three-pole for all
Three-Pole Reclose faults inside the stage selected for reclosure. The auto reclose function is then started.
Cycle When the trip command resets or the circuit breaker opens (auxiliary contact criterion)
an (adjustable) dead time starts. At the end of this dead time, the circuit breaker re-
ceives a close command. At the same time the (adjustable) reclaim time is started. If
during configuration of the protection function address 134 AR control mode =
with Pickup ...was set, different dead times can be parameterized depending on
the type of protection pickup.
If the fault is cleared (successful reclosure), the reclaim time expires and all functions
return to their quiescent state. The fault is cleared.
If the fault is not cleared (unsuccessful reclosure), the short-circuit protection issues a
final trip with the protection stage that is selected to operate without reclosure. Any
fault during the reclaim time leads to a final trip.
After unsuccessful reclosure (final tripping) the automatic reclosure is blocked dynam-
ically (see also margin heading„Reclose Block", above).
The sequence above applies for single reclosure cycles. In 7SD5 multiple reclosure
(up to 8 cycles) is also possible (see below).
Sequence of a Single-pole reclose cycles are only possible with the appropriate device version and if
this was selected during the configuration of the protection functions (address 110
Single-Pole
Trip mode, see also Section 2.1.1.3). Of course, the circuit breaker must also be suit-
Reclose Cycle
able for single-pole tripping.
If the automatic reclosure function is ready, the short-circuit protection trips single pole
for all single-phase faults inside the stage selected for reclosure. Under the general
settings (address 1156 Trip2phFlt, see also Section 2.1.4.1) it can also be select-
ed that single-pole tripping takes place for two-phase faults without earth. Single-pole
tripping is of course only possible with short-circuit protection functions that can deter-
mine the faulty phase.
If only single-pole reclosure is selected, then the fault protection issues a final three-
pole trip with the stage that is valid/selected without reclosure. Any three-pole trip is
final. The automatic reclose function is blocked dynamically (see also margin heading
„Reclosure Block", above).
The automatic reclosure function is started following a single-pole trip. The (adjust-
able) dead time for the single-pole reclose cycles starts with reset of the trip command
or opening of the circuit breaker pole (auxiliary contact criterion). After expiry of the
dead time, the circuit breaker receives a close command. At the same time, the (ad-
justable) reclaim time is started. If the reclosure is blocked during the dead time fol-
lowing a single-pole trip, immediate three-pole tripping can take place as an option
(forced three-pole coupling).
If the fault is cleared (successful reclosure), the reclaim time expires and all functions
return to their quiescent state. The fault is cleared.
If the fault is not cleared (unsuccessful reclosure), the short-circuit protection issues a
final trip with the protection stage that is valid/selected without reclosure. All faults
during the reclaim time also lead to the issue of a final three-pole trip.
After unsuccessful reclosure (final tripping) the automatic reclosure is blocked dynam-
ically (see also margin heading„Reclose Block", above).
The sequence above applies for single reclosure cycles. In 7SD5 multiple reclosure
(up to 8 cycles) is also possible (see below).
7SD5 Manual
C53000-G1176-C169-1
2.15 Automatic Reclosure Function (optional)
291