Figure 287: 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
Rated Op current
setting, the remaining operation of the breaker reduces by
one operation. If the tripping current is more than the rated fault current set with
the
Rated fault current
setting, the possible operations are zero. The remaining
life of the tripping current in between these two values is calculated based on the
trip curve given by the manufacturer. The
Op number rated
and
Op number fault
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
CB wear values
in the clear menu from WHMI or LHMI.
Clearing
CB wear values
also resets the operation counter.
Alarm limit check
When the remaining life of any phase drops below the
Life alarm level
threshold
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
Initial CB Rmn life
parameter and resetting the value via
the clear menu from WHMI or LHMI.
7.1.4.7 Circuit breaker spring-charged indication
The circuit breaker spring-charged indication subfunction calculates the spring
charging time.
The operation of the subfunction can be described with a module diagram. All the
modules in the diagram are explained in the next sections.
1MRS758755 C
Condition monitoring functions
REC615 & RER615
Technical Manual
559
To Next Page
Loading...
