ABB OMD800 - No Line Priority

10
AUTOMATIC CONTROL UNIT, OMD800
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3.1.2 No line priority
The switching sequence of OMD800 can be summarized in following steps:
An anomaly occurs on the Line 1
Switching delay
Generator start
Delay on transfer
If Pre-transfer signal active: Pre-transfer signal output on,
Pre-transfer I to II delay
Change-over switch (Switch I) to the position O
Dead band I to II delay
Change-over switch (Switch II) to the position II
If Pre-transfer signal active: Pre-transfer signal output off
And the back switching sequence can be summarized in the following steps:
The Line 1 will start the normal functioning
An anomaly occurs on the Line 2
Switching delay
If Pre-transfer signal active: Pre-transfer output on, Pre-transfer II to I delay
Change-over switch (Switch II) to the position O
Dead band II to I delay
Change-over switch (Switch I) to the position I
If Pre-transfer signal active: Pre-transfer output off
Generator stop delay
Generator stop
Ts: Switching delay, Tt: Delay on transfer, Ds: Dead band I to II, TBs: Back switching delay, DBs: Dead band II to I, Gs: Generator stop delay
Figure 3.2 Automatic Switching Sequence, no line priority
Ts Tt Ds TBs DBs Gs
LINE 1
LINE 2
Switch I status
Switch II status
Gen. start