11
Multiple UPS Operation (Parallel)
The diagrams and procedures in this section apply to a parallel configuration where multiple UPS Power Modules (up to eight) are connected to a
single equipment load. A parallel configuration provides fail-safe redundancy, assuring that the load is constantly supported even if one or more
UPS Systems fail or are taken off-line for maintenance. Two or more UPSs operating in parallel must have the same VA capacities, output voltage
and frequency. They also must be able to assume an equal share of the equipment load in order to not overload the UPSs and switch all UPSs to
Reserve AC Input Supply Mode.
• Operational Modes
• Optional Parallel Configurations (Hot Standby Redundancy and Common Battery)
• Start-Up Procedure
• Shutdown Procedure
• Manual Maintenance Bypass Procedure
Operational Modes
Normal Mode
In this mode, the power modules continuously convert AC input power into DC power (to recharge their batteries and supply their inverters). Their
inverters, in turn, transform DC power into clean, stable AC output power for the connected equipment load.