Siemens siprotec 7SA522 User Manual

2.13 Automatic reclosure function (optional)
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7SA522 Manual
C53000-G1176-C155-3
cycles are not allowed, the reclosure is locked out dynamically. The trip command is
final.
The latter also applies if the CB trips two poles following a single-pole trip command.
The device can only detect this if the auxiliary contacts of each pole are connected in-
dividually. The device immediately initiates three pole coupling thus resulting in a
three-pole trip command.
If the CB auxiliary contacts indicate that at least one further pole has opened during
the dead time following a single-pole trip, a three-pole reclose cycle is initiated with the
dead time for three-pole reclosure if this is allowed. If the auxiliary contacts are con-
nected for each pole individually, the device can detect a two-pole open CB. In this
case the device immediately sends a three-pole trip command provided the forced
three-pole trip is activated (see Subsection 2.13.2 at margin heading “Forced Three-
Pole Trip”).
Sequence of a
Three-Pole Reclose
Cycle
If the automatic reclosure function is ready, the short-circuit protection trips three pole
for all faults inside the stage selected for reclosure. The automatic reclosure function
is then started. 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 receives a close command. At the same time the (adjustable) reclaim
time is started. If during configuration of the protection functions address  $5
FRQWUROPRGH = 3,&.83 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 dy-
namically (see also margin heading “ Reclose Block, above”).
The sequence above applies for single reclosure cycles. In 7SA522 multiple reclosure
(up to 8 cycles) is also possible (see below).
Sequence of a
Single-pole
Reclose Cycle
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 
7ULSPRGH, see also Section 2.1.1.2). Of course, the circuit-breaker must also be
suited 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  7ULSSK)OW, see also Section 2.1.5.1) 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 short-circuit protection issues a final
three pole trip with the stage that is valid/selected without reclosure. Every three-pole
trip is final. The automatic reclosure 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

Siemens siprotec 7SA522 Specifications

General

Brand	Siemens
Model	siprotec 7SA522
Category	Protection Device
Language	English