Siemens 7SR51 - Logic of the Function; Application and Setting Notes

Logic of the Function
[lo_7SR5_81logicdiagram, 1, en_US]
Figure 5-51
Logic Diagram: 81 Frequency Protection – "f>" or "f<"
Application and Setting Notes
Parameter: Element
•
Default setting: Disabled
This setting is used to allow the element to be switched on and off if it is not required. A separate setting
is provided for each element. These setting can be used to select the number of elements required.
Parameter: Input Selection
•
Default setting: VT1/2/3
Each 81 element can be individually set to measure frequency from the 3 phase VT inputs or single phase
VT input.
Parameter: Operation
•
Default setting: Under
Each 81 element can be individually set to be either an underfrequency or overfrequency element.
5.27.3
5.27.4
Protection and Automation Functions
5.27 81 Frequency Protection – "f>" or "f<"
Reyrolle 7SR5, Overcurrent Protection Device, Device Manual 343
C53000-G7040-C014-1, Edition 11.2019