ABB Relion Technical Manual page 618

Section 14
Monitoring
612
I_A
I_B
I3P
I_C
POSCLOSE
IACCRST
BLOCK
BLK_ALM
GUID-DAC3746F-DFBF-4186-A99D-1D972578D32A-ANSI V1 EN
Figure 270: Functional module diagram for calculating accumulative energy and
alarm
Accumulated energy calculator
This module calculates the accumulated energy I
CurrExp setting.
The calculation is initiated with the POSCLOSE input open events. It ends when the RMS
current becomes lower than the AccDisLevel setting value.
GUID-75502A39-4835-4F43-A7ED-A80DC7C1DFA2 V1 EN
Figure 271: Significance of theDiffTimeCorr setting
The DiffTimeCorr 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 DiffTimeCorr setting. When the setting is negative, the calculation starts in
advance by the correction time before the auxiliary contact opens.
The accumulated energy outputs IACC_A (_B, _C) are available through the
Monitored data view on the LHMI or through tools via communications. The values can
Accumula-
Alarm limit
ted energy
check
calculator
y
t [(kA)
1MRK 502 048-UUS A
IACCLOAL
IACCALM
y
s]. The factor y is set with the
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