ABB 615 Series - Function Block; Functionality; Identification; Loss of Load Supervision 37 M

4.1.7 Loss of load supervision 37M
4.1.7.1 Identification
Function description
IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Loss of load supervision LOFLPTUC 3I< 37M
4.1.7.2 Function block
37
I_A
I_B
I_C
BLOCK
TRIP
PICKUP
GUID-79688824-6B61-45E2-B88B-60560AE5B51C V1 EN
Figure 137: Function block
4.1.7.3 Functionality
The loss of load supervision function 37M is used to detect a sudden load loss which is
considered as a fault condition.
37M picks up 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 trip 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.
4.1.7.4 Operation principle
The function can be enabled and disabled with the Operation setting. The corresponding
parameter values are “Enable” and “Disable”.
The operation of 37M can be described using a module diagram. All the modules in the
diagram are explained in the next sections.
1MAC059074-MB A Section 4
Protection functions
615 series ANSI 289
Technical Manual