ABB RER620 Technical Manual page 331

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RER620
Technical Manual
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 304: Live dead mode of operation under which switching can be carried out
Live dead mode Description
Both Dead Both Line and Bus de-energized
Live L, Dead B Bus de-energized and Line energized
Dead L, Live B Line de-energized and Bus energized
Dead Bus, L Any Both Line and Bus de-energized or Bus de-energized and Line energized
Dead L, Bus Any Both Line and Bus de-energized or Line de-energized and bus energized
One Live, Dead Bus de-energized and Line energized or Line de-energized and Bus energized
Not Both Live Both Line and Bus de-energized or Bus de-energized and Line energized or Line
de-energized and Bus energized
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 make sure 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 operate time, timer is reset and the procedure is
restarted when the conditions allow again. 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 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 settings
parameters.
In synch-check function the two voltage inputs are referred to as Bus and Line while in
RER620 the inputs are referred to as Source-1 and Source-2. Unless otherwise indicated
consider Source-1 as Bus and Source-2 as Line side. For example if Source 2 voltage goes
below the 'dead' threshold setting, the same will be considered as Line Dead as TRUE
by synchro-check function. If Source 2 voltage goes above 'live' threshold, the Live Line
will be TRUE
Synch-check
The synch-check function measures the difference between the line voltage and bus
voltage. The function permits the closing of the circuit breaker when the following
conditions are simultaneously fulfilled.
Section 5
Control functions
325