ABB OTM C 21D User Manual

5
AUTOMATIC TRANSFER SWITCH, OTM_C_21D
And the return sequence can be summarized in
the following steps:
• The Line 1 will start the normal functioning
• Return delay TBs
• Change-over switch (Switch II) to the position 0
• Change-over switch (Switch I) to the position I
• Generator stop delay Gs
• Generator stop
Figure 2. Automatic Switching Sequences in OTM_C_21D, Line 1 priority
The transfer sequence of OTM_C21D can be sum-
marized in following steps:
• An anomaly occurs on the Line 1 (LN1)
• Generator start, immediately start generator in
case of black-out, phase-loss, overvoltage or
undervoltage (If Generator mode is selected)
• The Line 2 start the normal functioning,
transfer delay Ts
• Change-over switch (Switch I) to the position 0
• Change-over switch (Switch II) to the position II
—
2.2 OTM_C21D switching sequence
2.2.1 Line 1 Priority (default mode)

ABB OTM C 21D Specifications

General

Brand	ABB
Model	OTM C 21D
Category	Switch
Language	English