ABB RER620 Technical Manual page 377

1MAC309294-MB F
RER620
Technical Manual
current is 10 kA, the operation counts from the curve at 10kA is about 60. One operation
at 10 kA will result in a reduction in the breaker life by 30,000/60=500 operations. If the
remaining life of the circuit breaker is 15,000 operations prior to this tripping, after one
operation of 10 kA, the remaining life of the circuit breaker is 15,000-500=14,500 at the
rated operating current. Breaker life reduction for one operation at current level I can also
be estimated by the following formula,
Remaining life reduction =
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 operations
are locked. A binary input is available based on the pressure levels in the function, and
alarms are generated based on these inputs.
Condition monitoring functions
- Directional Coef
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r
Section 6
371