ABB RELION 620 Series Technical Manual page 1004

Section 9
Control functions
9.3.4
998
Operation principle
The function can be enabled and disabled with the Operation setting. The
corresponding parameter values are "On" and "Off".
SECRSYN has two parallel functionalities, the synchro check and energizing check
functionality. The operation of SECRSYN can be described using a module diagram.
All the modules in the diagram are explained in the next sections.
GUID-FE07029C-C6C1-4BA7-9F8E-CACE86D0A9BD V2 EN
Figure 514: Functional module diagram
If Energizing check is passed, no further conditions need to be fulfilled to permit
closing. Otherwise, Synchro check function can operate either with the U_AB or U_A
voltages. The selection of used voltages is defined with the VT connection setting of
the line voltage general parameters.
By default, voltages U_BUS and U_LINE are connected as presented
in Figure
Voltage source switch to "True".
Energizing check
The Energizing check function checks the energizing direction. Energizing is defined
as a situation where a dead network part is connected to an energized section of the
network. The conditions of the network sections to be controlled by the circuit
breaker, that is, which side has to be live and which side dead, are determined by the
setting. A situation where both sides are dead is possible as well. The actual value for
defining the dead line or bus is given with the Dead bus value and Dead line value
settings. Similarly, the actual values of live line or bus are defined with the Live bus
value and Live line value settings.
Energizing
check
Synchro
check
523. If necessary, connections can be switched by setting
1MRS757644 F
620 series
Technical Manual