ABB RELION SMU615 Technical Manual page 172

Condition monitoring functions
The IPOW_ALM and IPOW_LO outputs can be blocked by activating the binary input
BLOCK.
6.1.4.6 Remaining life of circuit breaker
Every time the breaker operates, the life of the circuit breaker reduces due to
wearing. The wearing in the breaker depends on the tripping current, and the
remaining life of the breaker is estimated from the circuit breaker trip curve
provided by the manufacturer. The remaining life is decremented at least with one
when the circuit breaker is opened.
The operation of the remaining life of the circuit breaker subfunction can be
described with a module diagram. All the modules in the diagram are explained
in the next sections.
Figure 116: Functional module diagram for estimating the life of the circuit breaker
Circuit breaker life estimator
The circuit breaker life estimator module calculates the remaining life of the circuit
breaker. If the tripping current is less than the rated operating current set with
the
one operation. If the tripping current is more than the rated fault current set with
the
life of the tripping current in between these two values is calculated based on the
trip curve given by the manufacturer. The
parameters set the number of operations the breaker can perform at the rated
current and at the rated fault current, respectively.
The remaining life is calculated separately for all three phases and it is available as
a monitored data value CB_LIFE_A (_B,_C). The values can be cleared by setting
the parameter
Alarm limit check
When the remaining life of any phase drops below the
setting, the corresponding circuit breaker life alarm CB_LIFE_ALM is activated.
It is possible to deactivate the CB_LIFE_ALM alarm signal by activating the binary
input BLOCK. The old circuit breaker operation counter value can be taken into use
by writing the value to the
the clear menu from WHMI.
172
Rated Op current setting, the remaining operation of the breaker reduces by
Rated fault current setting, the possible operations are zero. The remaining
CB wear values in the clear menu from WHMI.
CB wear values also resets the operation counter.
Clearing
Op number rated and Op number fault
Initial CB Rmn life parameter and resetting the value via
1MRS758407 C
Life alarm level threshold
Technical Manual
SMU615