ABB OTM C 21D User Manual

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AUTOMATIC TRANSFER SWITCH, OTM_C_21D
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1. Symbols & Terms
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1.1 Use of symbols
Risk of Electric shock: warns about a situation where a hazardous voltage may cause phys-
ical injury to a person or damage to equipment.
General warning: warns about a situation where something other than electrical equip-
ment may cause physical injury to a person or damage to equipment.
Caution: provides important information or warns about a situation that may have a detri-
mental effect on equipment.
Information: provides important information about the equipment.
Table 1. Explanations of abbreviations and terms
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1.2 Explanations of abreviations and terms
OTM_C21D Automatic transfer switch, the type name
LN1-Switch I Power supply line, e.g. the primary line
LN2-Switch II Power supply line, e.g. the secondary line used in emergency cases
EMRG OFF Used to drive the automatic transfer switch transfers to the “O” position when
receiving EMRG OFF signal.
AUTO Automatic mode
Remote test A sequence to test the functionality of the automatic transfer switch
Ts Transfer delay
TBs Return delay
OV Adjustable overvoltage threshold
UV Adjustable undervoltage threshold

ABB OTM C 21D Specifications

General

Brand	ABB
Model	OTM C 21D
Category	Switch
Language	English