Operation
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3.3 Modes of Operation
This section illustrates the flow of power through circuit breakers, switches and UPS components
during various modes of operation. An SCCT with three modules is shown. The same modes of opera-
tion apply to all configurations of the Liebert Series 610 UPS multi-module system. Highlighted
(thick) lines in the diagrams indicate power flow and power availability.
These illustrations show a three-breaker maintenance bypass because it is commonly used. Your instal-
lation may have a two-breaker, three-breaker or four-breaker maintenance bypass or none at all.
These illustrations do not show an alternate power source (generator) and automatic transfer switch
(external to the UPS) that might be present at your installation.
Table 12 below lists abbreviations for circuit breakers used in this manual.
Table 12 Circuit breaker abbreviations
Abbreviation Circuit Breaker
BFB Bypass Feeder Breaker
BIB Bypass Input Breaker
CB1 Module Input Breaker
CB2 Module Output Breaker
MBB Maintenance Bypass Breaker
MBD Module Battery Disconnect
MIB Maintenance Isolation Breaker
RIB Rectifier Input Breaker
SBB System Bypass Breaker