Siemens SIPROTEC 7VU681, User Manual

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Function
2.1 ATS
SIPROTEC, 7VU681, User Manual
C53000-G1176-C368-1, Release Date 07.2012 43
2.1.5 User-Specified ATS
When the default transfer modes cannot meet the requirements of special applications, you can define their
own transfer logics via the CFC.
CFC is programmable logic tool with graphical interface. It supports the arithmetic operation, logic operation
and relational operation with analog input. Please refer to the DIGSI CFC manual for the details.
2.1.6 Load Shedding
Load shedding function has 2 stages with different tripping delay, both are independent with ATS logics. Load
shedding can be started by ATS succeeded signals with parameter control and external signals without
parameter control.
When you define own transfer logics, the transfer successful result can be connected with the signals 17900
>Start LSH L1
and 17901 >Start LSH L2 to start load shedding function.
Figure 2-23 Logic Diagram of Load Shedding Started by ATS Succeeded Signals