ABB RELION 620 Series Technical Manual page 927

1MRS757644 F
7.1.5
620 series
Technical Manual
The operation of the subfunction can be described with a module diagram. All the
modules in the diagram are explained in the next sections.
A071113 V2 EN
Figure 486: Functional module diagram for circuit breaker gas pressure alarm
The gas pressure is monitored through the binary input signals PRES_LO_IN and
PRES_ALM_IN.
Timer 1
When the PRES_ALM_IN binary input is activated, the PRES_ALM alarm is
activated after a time delay set with the Pressure alarm time setting. The PRES_ALM
alarm can be blocked by activating the BLOCK input.
Timer 2
If the pressure drops further to a very low level, the PRES_LO_IN binary input
becomes high, activating the lockout alarm PRES_LO after a time delay set with the
Pres lockout time setting. The PRES_LO alarm can be blocked by activating the
BLOCK input.
Application
SSCBR includes different metering and monitoring subfunctions.
Circuit breaker status
Circuit breaker status monitors the position of the circuit breaker, that is, whether the
breaker is in an open, closed or intermediate position.
Circuit breaker operation monitoring
The purpose of the circuit breaker operation monitoring is to indicate that the circuit
breaker has not been operated for a long time. The function calculates the number of
days the circuit breaker has remained inactive, that is, has stayed in the same open or
closed state. There is also the possibility to set an initial inactive day.
Breaker contact travel time
High traveling times indicate the need for the maintenance of the circuit breaker
mechanism. Therefore, detecting excessive traveling time is needed. During the
opening cycle operation, the main contact starts opening. The auxiliary contact A
Condition monitoring functions
Section 7
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