ABB Relion 670 series, Applications Manual

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17.3.2 Application
GUID-140AA10C-4E93-4C23-AD57-895FADB0DB29 v5
Liquid medium supervision (SSIML) is used for monitoring the circuit breaker condition. Proper
arc extinction by the compressed oil in the circuit breaker is very important. When the level
becomes too low, compared to the required value, the circuit breaker operation is blocked to
minimize the risk of internal failures. Binary information based on the oil level in the circuit
breaker is used as input signals to the function. In addition to that, the function generates
alarms based on received information.
17.4 Breaker monitoring SSCBR
17.4.1 Identification
GUID-0FC081B2-0BC8-4EB8-9529-B941E51F18EE v7
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Breaker monitoring SSCBR - -
17.4.2 Application
GUID-45572680-3A39-4B3C-8639-4E4C5A95AA26 v8
The circuit breaker maintenance is usually based on regular time intervals or the number of
operations performed. This has some disadvantages because there could be a number of
abnormal operations or few operations with high-level currents within the predetermined
maintenance interval. Hence, condition-based maintenance scheduling is an optimum solution
in assessing the condition of circuit breakers.
Circuit breaker contact travel time
Auxiliary contacts provide information about the mechanical operation, opening time and
closing time of a breaker. Detecting an excessive traveling time is essential to indicate the
need for maintenance of the circuit breaker mechanism. The excessive travel time can be due
to problems in the driving mechanism or failures of the contacts.
Circuit breaker status
Monitoring the breaker status ensures proper functioning of the features within the
protection relay such as breaker control, breaker failure and autoreclosing. The breaker status
is monitored using breaker auxiliary contacts. The breaker status is indicated by the binary
outputs. These signals indicate whether the circuit breaker is in an open, closed or error state.
Remaining life of circuit breaker
Every time the breaker operates, the circuit breaker life reduces due to wear. The wear in a
breaker depends on the interrupted current. For breaker maintenance or replacement at the
right time, the remaining life of the breaker must be estimated. The remaining life of a breaker
can be estimated using the maintenance curve provided by the circuit breaker manufacturer.
Circuit breaker manufacturers provide the number of make-break operations possible at
various interrupted currents. An example is shown in Figure 401 .
Section 17 1MRK 505 343-UEN B
Monitoring
662
Application manual