Section 4
Protection functions
4.1.9
4.1.9.1
4.1.9.2
4.1.9.3
4.1.9.4
338
Loss of load supervision LOFLPTUC
Identification
Function description
Loss of load supervision
Function block
GUID-B7774D44-24DB-48B1-888B-D9E3EA741F23 V2 EN
Figure 165:
Function block
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.
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.
GUID-4A6308B8-47E8-498D-A268-1386EBBBEC8F V1 EN
Figure 166:
Functional module diagram
IEC 61850
IEC 60617
identification
identification
LOFLPTUC
3I<
1MRS757644 F
ANSI/IEEE C37.2
device number
37
620 series
Technical Manual