7
AU TO M AT I C T R A N SFER S W I TC H , OT M _ C _ 2 1 D
• An anomaly occurs on the Line 1 (LN1)
• Switching delay Ts, in case of phase-loss, over-
voltage and under voltage conditions
• Generator start, immediate start generator in
case of black-out, in case of phase-loss, over-
voltage or undervoltage after switching delay
Ts (if Generator mode is selected)
• Change-over switch (Switch I) to the
position 0
• Change-over switch (Switch II) to the
position II
Figure 4. Automatic Switching Sequences in OTM_C_21D, Manual back switching mode
LN1
LN2
Switch I status
Switch II status
Ts
The back switching sequence can be
summarized in the following steps:
• The Line 1 will start the normal functioning
• Change-over switch stays in position II
• An anomaly occurs on the Line 2 (LN2)
• Change-over switch stays in position II
• Change-over switch can be trans ferred
manually back to position I
The switching sequence of OTM_C_21D can be
summarized in following steps:
Manual back switching mode
