Ats; General - Siemens SIPROTEC 7VU681 User Manual

Function

2.1 ATS

2.1
ATS
2.1.1

General

Here are the basic requirements of ATS function:
1. When the busbar voltage is dead, the standby voltage is normal and there is no blocking condition, ATS start.
2. ATS cannot start when the CB of the operating power supply is opened manually.
3. Before ATS releases the close command to the CB of the standby power supply, it must confirm that the CB
of operating power supply is opened.
4. Transfer operation can be started only after ATS is Ready.
The control conditions of the ATS can be divided to 3 categories: Ready condition, blocking condition and
pickup condition.
When all Ready conditions are fulfilled without any blocking condition, ATS becomes Ready after a time delay
(8938 Time Delay to Ready Status). When all pickup conditions are fulfilled, ATS starts after a time delay and
transfers the power supply.
The following diagram shows the general logic of Ready conditions, blocking conditions and pickup conditions.
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SIPROTEC, 7VU681, User Manual
C53000-G1176-C368-1, Release Date 07.2012