Siemens siprotec 7SA522, User Manual

Page: 387 / 628

Functions
6-239
7SA522 Manual
C53000-G1176-C119-2
ping protection function resets very rapidly. Only after the last protection function has
reset (no function is picked up any more)
AND the minimum trip command duration
has expired, the trip commands can reset.
A further condition for the reset of the trip command is that the circuit breaker has
opened, in the event of single-pole tripping the relevant circuit-breaker pole. In the
function control of the device this is checked by means of the circuit-breaker position
feedback (Subsection 6.17.2) and the flow of current.
Figure 6-126 Latching and reset of the trip command
Automatic
Reclosure Inter-
locking When tripping the circuit-breaker with a protection function the automatic reclosure
must often be blocked until the cause for the protection function operation is found.
7SA522 therefore provides the integrated automatic reclosure interlocking function.
The interlocking state (“
/2&.287
”) will be realized by a RS flipflop which is protected
against auxiliary voltage failure (see Figure 6-127). The RS flipflop will be set via a bi-
nary input “
!/RFNRXW6(7
” (FNo 385). With the output alarm “
/2&.287
” (FNo 530),
if interconnected correspondingly, a reclosure of the circuit-breaker
(e.g. for automatic reclosure, manual close signal, synchronization, closing via control)
can be blocked. Only once the cause for the protection operation is known, should the
interlocking be reset by a manual reset via binary input ”
!/RFNRXW5(6(7
” (FNo
386).
Figure 6-127 Automatic reclosure interlocking
T
70LQ75,3&0'
S
R
Q
&
TRIP L1
fr
om
the
prot
. functions
S
R
Q
TRIP L2
S
R
Q
TRIP L3
≥
1
CB open L1
Relay TRIP L3
Relay TRIP L2
&
&
&
CB open L2
CB open L3
Relay TRIP L1
S
R
Q
>LOCKOUT Set
>LOCKOUT Reset
LOCKOUT
FNo
FNo
FNo