The calculation is initiated with the POSCLOSE input opening events. It ends when
the RMS current becomes lower than the
Acc stop current
setting value.
Figure 286: Significance of the Difference Cor time setting
The
Difference Cor time
setting is used instead of the auxiliary contact to
accumulate the energy from the time the main contact opens. If the setting is
positive, the calculation of energy starts after the auxiliary contact has opened and
when the delay is equal to the value set with the
Difference Cor time
setting. When
the setting is negative, the calculation starts in advance by the correction time
before the auxiliary contact opens.
The accumulated energy outputs IPOW_A (_B, _C) are available in the monitored
data view on the LHMI or through tools via communications. The values can be reset
by setting the parameter
Initial CB Rmn life
setting to true in the clear menu from
WHMI or LHMI.
Alarm limit check
The IPOW_ALM alarm is activated when the accumulated energy exceeds the value
set with the
Alm Acc currents Pwr
threshold setting. However, when the energy
exceeds the limit value set with the
LO Acc currents Pwr
threshold setting, the
IPOW_LO output is activated.
The IPOW_ALM and IPOW_LO outputs can be blocked by activating the binary input
BLOCK.
7.1.4.6 Remaining life of circuit breaker
Every time the breaker operates, the life of the circuit breaker reduces due to
wearing. The wearing in the breaker depends on the tripping current, and the
remaining life of the breaker is estimated from the circuit breaker trip curve
provided by the manufacturer. The remaining life is decremented at least with one
when the circuit breaker is opened.
The operation of the remaining life of the circuit breaker subfunction can be
described with a module diagram. All the modules in the diagram are explained
in the next sections.
Condition monitoring functions
1MRS758755 C
558 REC615 & RER615
Technical Manual
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