Loss Of Load Supervision Loflptuc - ABB RELION 620 Series Technical Manual

1MRS757644 H
4.1.9

Loss of load supervision LOFLPTUC

4.1.9.1 Identification
Function description
Loss of load supervision
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
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
620 series
Technical Manual
IEC 61850 IEC 60617
identification identification
LOFLPTUC 3I<
Operation setting. The
Protection functions
ANSI/IEEE C37.2
device number
37
355