Function Control And Circuit Breaker Testing - Siemens SIPROTEC 7SA522 Manual

2 Functions
2.20

Function control and circuit breaker testing

2.20.1 Function control
Applications
2.20.1.1 Line Energization Recognition
330
The function control is the control centre of the device. It coordinates the sequence of
the protection and ancillary functions, processes their decisions and the information
coming from the power system.
• Line energization recognition,
• Processing of the circuit breaker position,
• Open Pole Detector,
• Fault detection logic
• Tripping logic.
During energization of the protected object, several measures may be required or de-
sirable. Following a manual closure onto a short-circuit, immediate trip of the circuit
breaker is usually required. In the distance protection for example, this is implemented
by activation of the overreaching zone Z1B and the switch on to fault function for a
short period following manual closure. In addition at least one stage of each short-
circuit protection function can be selected to trip without time delay following manual
closure as described in the corresponding sections. Also see Subsection 2.1.5.1 at
margin heading "Circuit Breaker Status".
The manual closing command must be indicated to the device via a binary input. In
order to be independent of the duration that the switch is closed, the command is set
to a defined length in the device (adjustable with the address  6, 7LPH
0DQ&O). Figure 2-147 shows the logic diagram.
7SA522 Manual
C53000-G1176-C155-3