ABB REC650 Applications Manual page 316

Section 12
Monitoring
310
B

log

A

Directional Coef =
I

log

I

A070794 V2 EN
I Rated operating current = 630 A
r
I Rated fault current = 16 kA
f
A Op number rated = 30000
B Op number fault = 20
Calculation for estimating the remaining life
The equation shows that there are 30,000 possible operations at the rated operating current
of 630 A and 20 operations at the rated fault current 16 kA. Therefore, if the tripping
current is 10 kA, one operation at 10 kA is equivalent to 30,000/500=60 operations at the
rated current. It is also assumed that prior to this tripping, the remaining life of the circuit
breaker is 15,000 operations. Therefore, after one operation of 10 kA, the remaining life
of the circuit breaker is 15,000-60=14,940 at the rated operating current.
Spring charging time indication
For normal circuit breaker operation, the circuit breaker spring should be charged within
a specified time. Therefore, detecting long spring charging time indicates the time for
circuit breaker maintenance. The last value of the spring charging time can be given 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.



= − . 2 2609

f


r
1MRK 511 286-UUS A
(Equation 93)
Application manual