Functions
2.25 Function Control and Circuit Breaker Test
SIPROTEC, 7SD5, Manual
C53000-G1176-C169-5, Release date 02.2011
443
2.25
Function Control and Circuit Breaker Test
2.25.1
Function Control
The function control is the control centre of the device. It coordinates the sequence of the protection and ancil-
lary functions, processes their decisions and the information coming from the power system.
Applications
• Line energization recognition,
• Processing of the circuit breaker position,
• Open Pole Detector,
• Fault detection logic,
• Tripping logic.
2.25.1.1 Line Energization Recognition
During energization of the protected object, several measures may be required or desirable. Following a
manual closure onto a short-circuit, immediate trip of the circuit breaker is usually desired. This is done, e.g. in
the overcurrent protection, by bypassing the delay time of a current stage. For every short-circuit protection
function which can be delayed, at least one stage can be selected that will operate instantaneously in the event
of a closing, as mentioned in the relevant sections. See also Section 2.1.4.1 side title „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
1150
SI Time Man.Cl
). This setting can only be changed using DIGSI at
Additional Settings
.
Figure 2-218 shows the logic diagram.
