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.
6.1.5
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 opens, the auxiliary contact B closes and the main contact reaches its opening
position. During the closing cycle, the first main contact starts closing. The auxiliary
contact B opens, the auxiliary contact A closes and the main contact reaches its
closed position. The travel times are calculated based on the state changes of the
auxiliary contacts and the adding correction factor to consider the time difference
of the main contact's and the auxiliary contact's position change.
Operation counter
Routine maintenance of the breaker, such as lubricating breaker mechanism, is
generally based on a number of operations. A suitable threshold setting to raise
an alarm when the number of operation cycle exceeds the set limit helps preventive
maintenance. This can also be used to indicate the requirement for oil sampling for
dielectric testing in case of an oil circuit breaker.
The change of state can be detected from the binary input of the auxiliary contact.
There is a possibility to set an initial value for the counter which can be used to
initialize this functionality after a period of operation or in case of refurbished
primary equipment.
Condition monitoring functions
1MRS758407 C
174
SMU615
Technical Manual
Summary of Contents for Relion SMU615
Page 1: ... RELION Substation Merging Unit SMU615 Technical Manual ...
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