ABB REB670 Applications Manual page 423

1MRK 505 337-UUS -
Application manual
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Interrupted current (kA)
IEC12000623 V1 EN
Figure 179: An example for estimating the remaining life of a circuit breaker
Calculation for estimating the remaining life
The graph shows that there are 10000 possible operations at the rated operating current
and 900 operations at 10 kA and 50 operations at rated fault current. Therefore, if the
interrupted current is 10 kA, one operation is equivalent to 10000/900 = 11 operations at
the rated current. It is assumed that prior to tripping, the remaining life of a breaker is
10000 operations. Remaining life calculation for three different interrupted current
conditions is explained below.
P1
2 5 10 20 50 100
IEC12000623_1_en.vsd
Section 14
Monitoring
P2
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