Functions
2.10 Automatic reclosure function (optional)
SIPROTEC, 6MD66x, Manual
C53000-G1876-C102-7, Release date 08.2011 129
breaker a recovery time after its previous trip before completing another close/trip cycle. This recovery time is
used, for instance, to build up sufficient air pressure for the next switching operations.
If the BI >CB ready goes ON again before the monitoring time has elapsed, the monitoring time will be reset,
and the AR continues.
• If the CB monitoring time is still running at the end of the regular dead time, the dead time will be extended
by the rest of the CB monitoring time. If the readiness of the CB returns within the maximum permissible
extension of the dead time defined by parameter T-DEAD EXT., and before expiry of the CB monitoring
time, the AR will be continued, and the monitoring time reset.
If the CB monitoring time is still running at the end of the maximum permissible extension of the dead time
defined by parameter T-DEAD EXT., the automatic reclosure function will be blocked dynamically.
If the monitoring time elapses before the circuit breaker signals its readiness, the automatic reclosure func-
tion will be blocked dynamically.
The dynamic blocking aborts the reclosure attempt. No CLOSE command is generated. After expiry of the
settable dynamic blocking time T BLK DYN, the AR will be reset.
Processing the Circuit Breaker Auxiliary Contacts
If the circuit breaker auxiliary contacts are connected to the device, the reaction of the circuit breaker is also
checked for plausibility . The circuit breaker auxiliary contacts can be connected to the device through the binary
inputs „>CB1 3p Closed“, „>CB1 3p Open“ and 1-pole >CB1Pole Lx. These binary signals inform the AR
whether the circuit breaker is open, closed or in intermediate position. No current criterion is used. Whether
auxiliary contacts are evaluated depends on which of them are allocated, if any.
• No CB auxiliary contact allocated
If no circuit breaker auxiliary contacts are allocated, the AR cannot detect the switching status of the circuit
breaker. Monitoring for "CB open without TRIP" and starting the dead time in dependence of the circuit
breaker feedback is not possible in this case. The AR is controlled by the TRIP command instead.
• Circuit breaker signal „>CB1 3p Open“ allocated
If binary signal „>CB1 3p Open“ alone is used, the circuit breaker is considered 3-pole open while the
signal is active. If the binary signal is active and no trip command applies, the automatic reclosure function
is statically blocked when it is in normal state, dynamically blocked when it is running and the „CB not
ready“ indication is output. The dead time is started while the automatic reclosure function is running if the
binary input becomes active following the trip command. An intermediate position of the circuit breaker
cannot be detected for this type of allocation.
• Circuit breaker signals „>CB1 3p Closed“ or >CB Pole Lx allocated
If binary signal „>CB1 3p Closed“ is used, the circuit breaker is considered 3-pole closed while the signal
is active. If the >CB Aux. Lx signals are allocated, the state of each pole of the cicru it breaker can be de-
termined what is especially important for a 1-pole reclosure. If such a binary signal is active and no trip
command applies, the automatic reclo s ure function is blocked statically when it is in normal state, dynami-
cally when it is running and the „CB not ready“ indication output. The dead time is started while the au-
tomatic reclosure function is running if the binary input becomes inactive following the trip command. An in-
termediate position of the circuit breaker cannot be detected for this type of allocation.
• Circuit breaker signals „>CB1 3p Open“ and „>CB1 3p Closed“ allocated
If both binary signals are used, the circu it breaker is considered open, when „>CB1 3p Open“ is active
and „>CB1 3p Closed“ inactive. An vice versa, the circuit breaker is considered closed, when „>CB1 3p
Open“ is inactive and „>CB1 3p Closed“ active. All other states are considered intermediate position. If
the circuit breaker is in intermediate position or opens without a trip command being detected, the automatic
reclosure is blocked statically when it is in normal state and dynamically when it is running. The start of the
dead time takes place while the automatic reclosure is running, when the circuit breaker is considered open.
The static blocking of the automatic reclosure function is indicated via the „AR is blocked“ indication,
dynamic via „AR is NOT ready“ and th e blocking cause via „CB not ready“ in both cases.