Ties and Interconnections

If the UPS sources are synchronized and are not overloaded, UPS systems may transfer load between each other. Except on a plant level, the UPS is the foundation of the multi corded system for critical loads.

All transfers are done via closed-transition, and the control systems for this type of operation are typically redundant or offer some other form of manual operation if the control system fails.

System ties are common in system-plus-system configurations, and several UPS system manufacturers offer pre-engineered solutions for this design feature. For xN or other types of UPS topologies, the system designer shall engineer a solution for the given UPS module and plant configuration.

Ties and interconnections should also prevent the propagation of failures and should limit short circuit fault current.