ABB RELION 620 Series Technical Manual page 759

1MAC504801-IB E
620 series ANSI
Technical Manual
The Synchro check function can operate either with the V_AB or V_A voltages. The
selection of used voltages is defined with the VT connection setting of the line voltage
general parameters.
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.
Table 545: Live dead mode of operation under which switching can be carried out
Live dead mode
Both Dead
Live L, Dead B
Dead L, Live B
Dead Bus, L Any
Dead L, Bus Any
One Live, Dead
Not Both Live
When the energizing direction corresponds to the settings, the situation has to be constant
for a time set with the Energizing time setting before the circuit breaker closing is
permitted. The purpose of this time delay is to ensure that the dead side remains de-
energized and also that the situation is not caused by a temporary interference. If the
conditions do not persist for a specified operation time, the timer is reset and the procedure
is restarted when the conditions allow. The circuit breaker closing is not permitted if the
measured voltage on the live side is greater than the set value of Max energizing V.
The measured energized state is available as a monitored data value ENERG_STATE and
as four function outputs LLDB (live line / dead bus), LLLB (live line / live bus), DLLB
(dead line / live bus) and DLDB (dead line / dead bus), of which only one can be active at
a time. It is also possible that the measured energized state indicates "Unknown" if at least
one of the measured voltages is between the limits set with the dead and live setting
parameters.
Control functions
Description
Both line and bus de-energized
Bus de-energized and line energized
Line de-energized and bus energized
Both line and bus de-energized or bus de-energized
and line energized
Both line and bus de-energized or line de-energized
and bus energized
Bus de-energized and line energized or line de-
energized and bus energized
Both line and bus de-energized or bus de-energized
and line energized or line de-energized and bus
energized
Section 9
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