- Two separate utility power sources
- Two separate circuit breaker panels
Site wiring decisions should be made with an understanding of how to benefit from the dual AC feature.
Separate Power Sources
Some sites have two separate sources of AC power. For example, a site may receive power from two different power substations. In this case, left-side AC feeder boxes can be connected to one source, and right-side AC feeder boxes can be connected to the other source. If the source supplying the AC feeder boxes on one side of the cabinet fails, the current on the AC feeder boxes on the other side of the cabinet will increase, allowing the system to continue operating.
Separate Circuit Breaker Panels
If there is concern about loss of power to the system during electrical maintenance work on the site, wire the system so left-side AC feeder boxes can be connected to one circuit breaker panel, and right-side AC feeder boxes can be connected to another circuit breaker panel. If the circuit breaker panel supplying the AC feeder boxes on one side of the cabinet is accidentally shut off, the current on the AC feeder boxes on the other side of the cabinet increases, allowing the system to continue operating.