ABB RELION SMU615 Technical Manual page 167

1MRS758407 C
Figure 108: Functional module diagram for monitoring circuit breaker status
Phase current check
This module compares the three phase currents to the setting
the current in a phase exceeds the set level, information about the phase is reported
to the contact position indicator module.
Contact position indicator
The OPENPOS output is activated when the auxiliary input contact POSCLOSE is
FALSE, the POSOPEN input is TRUE and all the phase currents are below the setting
Acc stop current .
The CLOSEPOS output is activated when the auxiliary POSOPEN input is FALSE and
the POSCLOSE input is TRUE.
The INVALIDPOS output is activated when both the auxiliary contacts have the
same value, that is, both are in the same logical level, or if the auxiliary input contact
POSCLOSE is FALSE and the POSOPEN input is TRUE and any of the phase currents
exceed the setting Acc stop current.
The status of the breaker is indicated by the binary outputs OPENPOS, INVALIDPOS
and CLOSEPOS for open, invalid and closed position respectively.
6.1.4.2 Circuit breaker operation monitoring
The purpose of the circuit breaker operation monitoring subfunction is to indicate if
the circuit breaker has not been operated for a long time.
The operation of the circuit breaker operation monitoring can be described with a
module diagram. All the modules in the diagram are explained in the next sections.
Figure 109: Functional module diagram for calculating inactive days and alarm for
circuit breaker operation monitoring
Inactivity timer
The module calculates the number of days the circuit breaker has remained inactive,
that is, has stayed in the same open or closed state. The calculation is done by
monitoring the states of the POSOPEN and POSCLOSE auxiliary contacts.
The inactive days INA_DAYS is available in the monitored data view. It is also
possible to set the initial inactive days with the
SMU615
Technical Manual
Condition monitoring functions
Acc stop current . If
Ini inactive days parameter.
167