ABB Relion 611 Series, Technical Manual

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4.1.4.10 Technical revision history
Table 133: JAMPTOC Technical revision history
Technical revision Change
B Internal improvement
C Internal improvement
4.1.5 Loss of load supervision LOFLPTUC
4.1.5.1 Identification
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Loss of load supervision LOFLPTUC 3I< 37
4.1.5.2 Function block
GUID-B7774D44-24DB-48B1-888B-D9E3EA741F23 V2 EN
Figure 63: Function block
4.1.5.3 Functionality
The loss of load supervision function LOFLPTUC is used to detect a sudden load loss
which is considered as a fault condition.
LOFLPTUC starts when the current is less than the set limit. It operates with the
definite time (DT) characteristics, which means that the function operates after a
predefined operate time and resets when the fault current disappears.
The function contains a blocking functionality. It is possible to block function outputs,
the definite timer or the function itself, if desired.
4.1.5.4 Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
The operation of LOFLPTUC can be described using a module diagram. All the
modules in the diagram are explained in the next sections.
1MRS757454 D
Section 4
Protection functions
611 series 141
Technical Manual