ABB 615 Series ANSI, Техническое руководство, Страница: 432 / 713

1MAC050144-MB C
Section 6
Supervision functions
615 series ANSI 425
Technical Manual
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
52CM 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 travelling times indicate the need for maintenance of the circuit breaker mechanism.
Therefore, detecting excessive travelling 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 close 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.
Accumulation of I
y
t
Accumulation of I
y
t calculates the accumulated energy Σ I
y
t where the factor y is known
as the current exponent. The factor y depends on the type of the circuit breaker. For oil