ABB RELION REX640 Technical Manual page 1438

Section 9
Control functions
1432
Table 1369: Live dead mode of operation when switching can be carried out
Live dead mode
Command
Off
Both Dead
Live B, Dead A
Dead B, Live A
Dead A , B Any
Dead B, A 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 CB closing is
permitted. This time delay ensures that the dead side remains de-energized and 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 it. The CB does not close 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 LADB (live bus A and dead bus B), LALB (live bus A and
live bus B), DALB (dead bus A and live bus B) and DADB (dead bus A and dead bus
B), of which only one can be active at a time. 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.
Synchronization check and control
The operation of Synchronization check and control modes can be described with a
module diagram.
Description
The Live dead mode setting uses Live dead mode
Ctl control command.
Live dead mode is set to "Off".
Both Bus A and Bus B de-energized
Bus B energized and Bus A de-energized
Bus B de-energized and Bus A energized
Bus A de-energized and Bus B energized or de-
energized
Bus B de-energized and Bus A energized or de-
energized
Bus A de-energized and Bus B energized or Bus B
de-energized and Bus A energized
Both Bus A and B de-energized or Bus A de-
energized and Bus B energized or Bus B de-
energized and Bus A energized
1MRS759142 C
REX640
Technical Manual