ABB RER620

Section 6 1MAC309294-MB F
Condition monitoring functions
366 RER620
Technical Manual
Figure 200: 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.
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 A(B,C) parameter and resetting the value via the clear
menu from WHMI or LHMI under the Clear CB wear values menu.
Clearing CB wear values also resets the operation counter.
CB life
estimator (A)
I_A
POSCLOSE_A
RST_CB_WEAR
BLOCK
Alarm limit
check
CB_LIFE_ALM
CB life
estimator (B)
I_B
POSCLOSE_B
CB life
estimator (C)
I_C
POSCLOSE_C