APC SYMMETRA 990 - Manual (Page 11)

Symmetra MW with External Bypass Static Switch Operation Manual - 990-1377D-001 7
Operation
Operation Modes
Normal operation
During online operation, the critical load is supported by the inverters. While the UPS system is operating
in this mode, a single-line diagram will appear on the screen. The green line indicates the power flow
from the utility, through the UPS units, and then to the load.
Battery operation
During battery operation, the critical load is supported by the inverters. The main inverter is supplied by
battery power, ensuring uninterrupted support to the load. While the UPS system is operating in battery
operation, a single-line diagram will appear on the screen. The green line indicates the power flow from
the batteries, through the main inverters, and then to the load.
Battery
Main Inverter Delta Inverter
External Bypass SSW
External Bypass SSW
Battery
Delta Inverter Main Inverter