ABB COM600 series User's & Technical Manual page 54

COM600 series 5.1 1MRS758734
Substation Analytics Technical Manual
Breaker contact travel time
High traveling times indicate the need for the maintenance of the circuit breaker mech-
anism. Therefore, detecting excessive traveling time is needed. During the opening cycle
operation, the main contact starts opening. The auxiliary contact A opens, the auxiliary
contact B closes and the main contact reaches its opening position. During the closing
cycle, the first main contact starts closing. The auxiliary contact B opens, the auxiliary
contact A closes and the main contact reaches its closed position. The travel times are
calculated based on the state changes of the auxiliary contacts and the adding correction
factor to consider the time difference of the main contact's and the auxiliary contact's
position change.
Operation counter
Routine maintenance of the breaker, such as lubricating breaker mechanism, is generally
based on a number of operations. A suitable threshold setting to raise an alarm when the
number of operation cycle exceeds the set limit helps preventive maintenance. This can
also be used to indicate the requirement for oil sampling for dielectric testing in case of
an oil circuit breaker.
The change of state can be detected from the binary input of the auxiliary contact. There
is a possibility to set an initial value for the counter which can be used to initialize this
functionality after a period of operation or in case of refurbished primary equipment.
Accumulation of I y t
Accumulation of I y t calculates the accumulated energy I y t, where the factor y is known
as the current exponent. The factor y depends on the type of the circuit breaker. For oil
circuit breakers, the factor y is normally 2. In case of a highvoltage system, the factor y
can be 1.4...1.5.
Spring-charged indication
For normal operation of the circuit breaker, the circuit breaker spring should be charged
within a specified time. Therefore, detecting long spring-charging time indicates that it
is time for the circuit breaker maintenance. The last value of the spring-charging time
can be used as a service value.
Gas pressure supervision
The gas pressure supervision monitors the gas pressure inside the arc chamber. When
the pressure becomes too low compared to the required value, the circuit breaker opera-
tions are locked. A binary input is available based on the pressure levels in the function,
and alarms are generated based on these inputs.
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