APC 990 User Manual
Operation: Operation Modes
8
Symmetra MW with External Bypass Static Switch Operation Manual - 990-1377D-001
Static bypass operation
During static bypass operation, the critical load is supplied directly by utility power. A single-line
diagram will appear on the screen with an orange line indicating the power flow through the External
Bypass Static Switch (SSW) to the load.
diagram will appear on the screen with an orange line indicating the power flow through the External
Bypass Static Switch (SSW) to the load.
Manual bypass operation
During maintenance bypass operation, the critical load is supplied directly by utility power. Maintenance
bypass allows the UPS units to be isolated for maintenance purposes. In maintenance bypass there is no
backup from the UPS system to the load. While the UPS system is operating in this mode, a single-line
diagram will appear on the screen with an orange line indicating the power flow from the utility to the
load through the Q3 breaker.
bypass allows the UPS units to be isolated for maintenance purposes. In maintenance bypass there is no
backup from the UPS system to the load. While the UPS system is operating in this mode, a single-line
diagram will appear on the screen with an orange line indicating the power flow from the utility to the
load through the Q3 breaker.
Main Inverter
Delta Inverter
Battery
External Bypass SSW
Main Inverter
Delta Inverter
Battery
External Bypass SSW