•
Manual closing has been detected (externally) and parameter BLOCK MC Dur. (T ≠ 0) was set so that
the automatic reclosing function responds to manual closing,
•
Via a correspondingly routed binary input (FNo. 2703
>BLOCK 79
). If the blocking takes places while the
automatic recloser is in normal state, the latter will be blocked statically (
79 is NOT ready
). The
blocking is terminated immediately when the binary input has been cleared and the automatic reclosure
function resumes normal state. If the automatic reclosure function is already running when the blocking
arrives, the dynamic blocking takes effect (
79 DynBlock
). In this case, the activation of the binary input
starts the dynamic blocking time SAFETY 79 ready. Upon its expiration, the device checks if the binary
input is still activated. If this is the case, the automatic reclosure program changes from dynamic blocking
to static blocking. If the binary input is no longer active when the time has elapsed and if no new
blocking conditions apply, the automatic reclosure system resumes normal state.
Status Recognition and Monitoring of the Circuit Breaker
Circuit Breaker Status
The detection of the actual circuit breaker status is necessary for the correct functionality of the automatic
reclosure function. The circuit breaker status is detected by the circuit breaker auxiliary contacts and is
communicated to the device via binary inputs 4602
>52-b
and 4601
>52-a
.
Here the following applies:
•
If binary input 4601
>52-a
and binary input 4602
>52-b
are used, the automatic reclosure function can
detect whether the circuit breaker is open, closed or in intermediate position. If both auxiliary contacts
detect that the circuit breaker is open, the dead time is started. If the circuit breaker is open or in inter-
mediate position without a trip command being present, the automatic reclosure function is blocked
dynamically if it is already running. If the automatic reclosure system is in normal state, it will be blocked
statically. When checking whether a trip command applies, all trip commands of the device are taken into
account irrespective of whether the function acts as starting or blocking element on behalf of the auto-
matic reclosure program.
•
If only the binary input 4601
>52-a
is allocated, the circuit breaker is considered open if the binary input
is not active. If the binary input gets inactive while no trip command of (any) function applies, the auto-
matic reclosure function is blocked. The blocking will be of static nature if the automatic reclosure func-
tion is in normal state at this time. If the automatic reclosing function is already running, there will be a
dynamic blocking. The dead time is started if the binary input gets inactive following the trip command of
a starting element (4601
>52-a
= inactive). An intermediate position of the circuit breaker cannot be
detected for this type of allocation.
•
If binary input 4602
>52-b
alone is allocated, the circuit breaker is considered open while the binary
input is active. If the binary input gets active while no trip command of (any) function applies, the auto-
matic reclosure function is blocked dynamically provided it is already running. Otherwise, there will be a
static blocking. The dead time is started if the binary input gets active following the trip command of a
starting element. An intermediate position of the circuit breaker cannot be detected for this type of allo-
cation.
•
If neither binary input 4602
>52-b
nor 4601
>52-a
are allocated, the automatic reclosure program
cannot detect the position of the circuit breaker. In this case, the automatic reclosure function will be
controlled exclusively via pickups and trip commands. Monitoring for "52-b without TRIP" and starting the
dead time in dependence of the circuit breaker feedback is not possible in this case.
Circuit Breaker Monitoring
The time needed by the circuit breaker to perform a complete reclose cycle can be monitored by the 7SJ62/64.
Breaker failure is detected:
A precondition for a reclosing attempt, following a trip command initiated by a protective relay element and
subsequent initiation of the automatic reclosing function, is that the circuit breaker is ready for at least one
TRIP-CLOSE-TRIP cycle. The readiness of the circuit breaker is monitored by the device using a binary input
>CB
Ready
. In the case where this signal from the breaker is not available, the circuit breaker monitoring feature
should be disabled, otherwise reclosing attempts will remain blocked.
2.16.3
Functions
2.16 Automatic Reclosing System 79
242 SIPROTEC 4, 7SJ62/64, Manual
C53000-G1140-C207-8, Edition 08.2016
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