Statistics; Description; Circuit Breaker Maintenance - Siemens 7SC80 Manual

Statistics

2.26.2
The number of trips initiated by the 7SC80 and the operating hours under load are counted. An additional
counter allows to determine the number of hours in which the switching device is in the "open" condition.
The counter and memory levels are protected against loss of auxiliary voltage.
During the first start of the device, the statistical values are pre-defined to zero.
2.26.2.1

Description

Number of Trips
In order to count the number of trips initiated by the 7SC80, the position of the circuit breaker auxiliary
contacts must be communicated to the 7SC80 via binary inputs. This requires the internal pulse counter „#of
TRIPs=" to be allocated in the matrix to a binary input that is controlled by the switching device OPEN position.
The pulse metered value
Metered Values Only" was enabled in the configuration matrix.
Number of Automatic Reclosing Commands
The number of reclosing commands initiated by the automatic reclosing function is summed up in separate
counters for the 1st and ≥ 2nd cycle.
Operating Hours
The operating hours under load are also stored (= the current value in at least one phase is greater than the
limit value BkrClosed I MIN set under address 212).
Hours Meter "CB open"
A meter can be realized as CFC application if it adds up the number of hours in state "CB open" similarly to the
operating hours meter. The universal hours meter is connected to a respective binary input and counts if this
binary input is active. Alternatively, the fact that the value falls below the parameter value 212 BkrClosed I
MIN may be used as a criterion for starting the meter. The meter can be set or reset. A CFC application
example for such a meter is available on the Internet (SIPROTEC Download Area).
2.26.2.2

Circuit Breaker Maintenance

General
The procedures aiding in CB maintenance allow maintenance intervals of the CB poles to be carried out when
their actual degree of wear makes it necessary. Saving on maintenance and servicing costs is one of the main
benefits this functionality offers.
The universal CB maintenance accumulates the tripping currents of the trips initiated by the protective func-
tions and comprises the four following autonomous subfunctions:
•
Summation tripping current (ΣΙ-procedure)
•
Summation of tripping powers (ΣΙ
•
Two-point procedure for calculating the remaining lifetime (2P-procedure)
•
Sum of all Squared Fault Current Integral (I
Measured value acquisition and preparation operates phase-selectively for all four subfunctions. The three
results are each evaluated using a threshold which is specific for each procedure (see
SIPROTEC Compact, 7SC80, Manual
E50417-G1140-C486-A8, Edition 07.2017
#of TRIPs= can be found in the "Statistics" group if the option "Measured and
x -procedure)
2 t-procedure);
Functions
2.26 Auxiliary Functions
Figure 2-122.).
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