Siemens 7SJ82, Manual

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Cold-Load Pickup Detection (Optional)
Logic
[loprocls-180912-01.tif, 1, en_US]
Figure 5-94 Logic Diagram of the Cold-Load Pickup Detection Function Block
The Cold-load pickup detection function block detects that a specific time has been exceeded after deactiva-
tion of the line or protected object. If you want to connect the protected object again, you must note that an
increased load-current requirement exists for a limited time after connection. This results from the nature of
the load.
The Cold-load pickup detection function block ensures that different parameters are used for an adjustable
time after connection. For example, for the time of the
Min. CB-open time
parameter, you can increase
the threshold value of a protection function or you can select a special characteristic curve.
If the Cold-load pickup detection function block detects an open feeder and the set time of the
Min. CB-
open time
parameter has expired, the indication
>Activate cold-load
is generated.
With the
>Activate cold-load
indication, you can activate a parameter set of the Cold-load pickup func-
tion. Via the binary input signal
>Activate cold-load
, you can also activate the
>Activate cold-load
indication directly.
If the Cold-load pickup detection function block detects closure and the corresponding load current, it starts
the time set in the
Dropout delay CB closed
parameter. The
>Activate cold-load
indication and
the activated parameter set are deactivated after this time has elapsed.
5.8.8
Function-Group Types
5.8 Process Monitor
298 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017