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Functions
2.25 Function Control and Circuit Breaker Test
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
445
If, however, external close commands which should not activate the manual close function are possible (e.g.
external reclosure device), the binary input
„>Manual Close“ must be triggered by a separate contact of the
control switch (Figure 2-220).
If in that latter case a manual close command can also be given by means of an internal control command from
the device, such a command must be combined with the manual CLOSE function via parameter
1152
Man.Clos. Imp. (Figure 2-218).
Figure 2-220 Manual closing with external automatic reclosure device
CB Circuit breaker
TC Circuit breaker close coil
CBaux Circuit breaker auxiliary contact
Besides the manual CLOSE detection, the device records any energization of the line via the integrated line
energization detection. This function processes a change-of-state of the measured quantities as well as the
position of the breaker auxiliary contacts. The current status of the circuit breaker is detected, as described in
the following Section at „Detection of the Circuit Breaker Position“. The criteria for the line energization detec-
tion change according to the local conditions of the measuring points and the setting of the parameter address
1134 Line Closure
(see Section 2.1.4 at margin heading „Circuit Breaker Status“).
The phase currents and the phase-to-earth voltages are available as measuring quantities. A flowing current
excludes that the circuit breaker is open (exception: a fault between current transformer and circuit breaker). If
the circuit breaker is closed, it may, however, still occur that no current is flowing. The voltages can only be
used as a criterion for the de-energised line if the voltage transformers are installed on the feeder side. There-
fore, the device only evaluates those measuring quantities that provide information on the status of the line ac-
cording to address
1134
.
But a change-of-state, such as a voltage jump from zero to a considerable value (address
1131
PoleOpenVoltage
) or the occurrence of a considerable current (address
1130 PoleOpenCurrent
), can be
a reliable indicator for line energization as such changes can neither occur during normal operation nor in case
of a fault. These settings can only be changed via DIGSI at
Display Additional Settings
.
The position of the auxiliary contacts of the circuit breakers directly indicate the position of the circuit breaker.
If the circuit breaker is controlled single-pole, energization takes place if at least one contact changes from open
to closed.
The detected energization is signalled through the message
„Line closure“
(No. 590). The parameter
1132 SI Time all Cl.
is used to set the signal to a defined length. These settings can only be changed
via DIGSI at
Display Additional Settings
. Figure shows the logic diagram.