4.1.9
Loss of load supervision LOFLPTUC
4.1.9.1
Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Loss of load supervision
LOFLPTUC
3I<
37
4.1.9.2
Function block
Figure 175: Function block
4.1.9.3
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.
4.1.9.4
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.
Figure 176: Functional module diagram
1MRS757644 H
Protection functions
620 series
Technical Manual
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