System Description
1.5.5Modes of Operation
See Figure 4.
The
1.Normal - Each load bus is fed from its respective UPS and the tie breaker is open. Each inverter is synchronized to its respective bypass source. Each load is supplied by its inverter(s), with its bypass available as an alternate source.
2.Momentary Tie - The load bus and the two UPSs are momentarily paralleled through the tie breaker. Both UPSs are
3.Combined Loads - Both loads are running on one UPS through the tie breaker. The combined loads are supplied by the selected UPS’s inverter(s), with that UPS’s bypass available as the alternate and sync source. This mode is typically used for servicing a UPS system, including its bypass and bypass transfer controls, without placing that UPS’s load on bypass.
4.Continuous Tie - The load bus and the available modules from the two UPS are continuously paralleled through the tie breaker. Both UPSs are
5.System Isolation - A selected load bus which has had all load removed (via shutdown, external maintenance bypass or downstream critical load switchover
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