Detection Of The Circuit Breaker Position - Siemens Siprotec 7VK61 Manual

Functions
2.8 Function Control
Figure 2-59
CB
ON
CBaux

2.8.1.2 Detection of the Circuit Breaker Position

For Protection Purposes
Information regarding the circuit breaker position is required by various protective and supplementary functions
to ensure their optimal functionality. This is, for example, of assistance for
• The circuit breaker failure protection (refer to Section 2.6),
• Verification of the dropout condition for the trip command (see Section „Terminating the Trip Signal").
The device is equipped with a circuit breaker position logic (Figure 2-60) which offers different options depend-
ing on the type of auxiliary contacts provided by the circuit breaker and on how they are connected to the
device.
In most cases it is sufficient to signal the position of the circuit breaker to the device with its auxiliary contact
via a binary input. This always applies if the circuit breaker is only switched three-pole. Then the NO auxiliary
contact of the circuit breaker is connected to a binary input which must be configured to the input function„>CB
3p Closed" (No. 379). The other inputs are then not used and the logic is basically restricted to simply
passing on this input information.
If the circuit breaker poles can be switched individually, and only a parallel connection of the NO individual pole
auxiliary contacts is available, the relevant binary input (BI) is allocated to the function „>CB 3p Open" (no.
380). The remaining inputs are not used in this case.
If the circuit breaker poles can be switched individually and if the individual auxiliary contacts are available, an
individual binary input should be used for each auxiliary contact if this is possible and if the device can and is
to trip single-pole. With this configuration, the device can process the maximum amount of information. Three
binary inputs are used for this purpose:
• „>CB Aux. L1" (No. 351) for the auxiliary contact of pole L1,
• „>CB Aux. L2" (No. 352) for the auxiliary contact of pole L2,
• „>CB Aux. L3" (No. 353) for the auxiliary contact of pole L3.
The inputs No. 379 and No. 380 are not used in this case.
If the circuit breaker can be switched individually, two binary inputs are sufficient if both the parallel as well as
series connection of the auxiliary contacts of the three poles are available. In this case, the parallel connection
of the auxiliary contacts is routed to the input function „>CB 3p Closed" (No. 379) and the series connection
is routed to the input function „>CB 3p Open" (No. 380).
152
Manual closing with external automatic reclosure device
Circuit breaker
Circuit breaker close coil
Circuit breaker auxiliary contact
SIPROTEC, 7VK61, Manual
C53000-G1176-C159-3, Release date 05.2009