Functions
2.22 Circuit Breaker Failure Protection
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
410
Single-stage circuit breaker failure protection
With single-stage operation, the adjacent circuit breakers (i.e. the circuit breakers of the busbar zone and, if
applicable, the circuit breaker at the remote end) are tripped after a delay time
T2
(address
3906
) should the
fault not have been cleared within this time.
The timers
T1-1pole
(address
3904
) and
T1-3pole
(address
3905
) are then set to
∞
since they are not
needed.
You can also use the first stage alone if you wish to use different delay times after 1-pole and 3-pole tripping of
the feeder protection. In this case set
T1-1pole
(address
3904
) and
T1-3pole
(address
3905
) separately,
but address
3903
1p-RETRIP (T1)
to
NO
to avoid a 1-pole trip command to the busbar. Set
T2
(address
3906
) to
∞
or equal to
T1-3pole
(address
3905
). Be sure that the correct trip commands are assigned to the
desired trip relay(s).
The delay time is determined from the maximum operating time of the feeder circuit breaker, the reset time of
the current detectors of the circuit breaker failure protection, plus a safety margin which allows for any tolerance
of the delay timers. The time sequence is illustrated in Figure 2-200. The dropout time for sinusoidal currents
is
≤
15 ms. If current transformer saturation is anticipated, the time should be set to 25 ms.
Figure 2-200
Time sequence example for normal clearance of a fault, and with circuit breaker failure, using
single-stage breaker failure protection
Circuit breaker not operational
These delays are not necessary if the control circuit of the local circuit breaker is faulted (e.g. control voltage
failure or air pressure failure) since it is apparent that the circuit breaker is not capable of clearning the fault. If
the relay is informed about this disturbance (via the binary input
„>CB faulty“
), the adjacent circuit breakers
(busbar and remote end if applicable) are tripped after the time
T3-BkrDefective
(address
3907
) which is
usually set to
0
.
Address
3908
Trip BkrDefect.
determines to which output the trip command is routed in the event that the
circuit breaker is not operational when a feeder protection trip occurs. Select that output which is used to trip
the adjacent circuit breakers (bus-bar trip).
Содержание SIPROTEC
Страница 20: ...Contents SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 20 ...
Страница 351: ...Functions 2 18 Synchronism and Voltage Check optional SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 351 ...
Страница 494: ...Functions 2 27 Command Processing SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 494 ...
Страница 640: ...Technical Data 4 27 Dimensions SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 640 ...
Страница 657: ...Appendix A 2 Terminal Assignments SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 657 7SD5 W ...
Страница 754: ...Appendix A 10 Measured Values SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 754 ...
Страница 756: ...Literature SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 756 ...
Страница 768: ...Glossary SIPROTEC 7SD5 Manual C53000 G1176 C169 5 Release date 02 2011 768 ...