ABB Relion SMU615, Technical Manual

Page: 176 / 272

I
r
Rated operating current = 630 A
I
f
Rated fault current = 16 kA
A Op number rated = 30000
B Op number fault = 20
Calculation for estimating the remaining life
Figure 119
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 30,000/60=500
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 15,000-500=14,500 at
the rated operating current.
Remaining life reduction
=






−
I
I
r
Directional Coef
(Equation 8)
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.
6.1.6 Signals
6.1.6.1 SSCBR Input signals
Table 196: SSCBR Input signals
Name Type Default Description
I_A SIGNAL 0 Phase A current
I_B SIGNAL 0 Phase B current
I_C SIGNAL 0 Phase C current
BLOCK BOOLEAN 0=False Block input status
POSOPEN BOOLEAN 0=False Signal for open po-
sition of apparatus
from I/O
Table continues on the next page
Condition monitoring functions 1MRS758407 C
176 SMU615
Technical Manual