2Nd Harmonic Block/Inrush Restraint (81Hbl2) - Siemens Reyrolle 7SR45 Argus Device Manual

3.10

2nd Harmonic Block/Inrush Restraint (81HBL2)

Overview of the Function (81HBL2)
The inrush-current detection is used to:
•
Recognize an inrush process on transformers and other inductive loads
•
Generate a blocking signal for protection functions when transformers are switched on
•
Allows a sensitive setting of the protection functions
NOTE
i
i
The 2nd harmonic block/inrush restraint supervision function (81HBL2) is not available for 7SR450[1/3]-
xGA10- 1AA0 MLFB variants.
Structure of the Function (81HBL2)
The Inrush Detector Supervision function element has group-dependent settings, these settings can be
different in each settings group – group numbers (Gn) 1 and 2.
The function monitors the primary system current using the 3-phase current transformer inputs, for example
CT1/2/3.
The inrush detector function (81HBL2) is summarized below:
•
High speed (instantaneous) operate characteristic
•
All phases are inhibited when any phase detects an inrush condition.
Logic of the Function (81HBL2)
[lo_7sr45_HarmonicBlockFeatureFn, 2, en_US]
Figure 3-13
Reyrolle, 7SR45, Device Manual
C53000-G7040-C101-2, Edition 09.2020
Logic Diagram of the 2nd Harmonic Block/Inrush Restraint (81HBL2)
3.10 2nd Harmonic Block/Inrush Restraint (81HBL2)
Functions
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