"Power company traces Super Bowl outage to electrical relay device." -- CNN (1 Viewer)

[Coe]

The new design implemented by Entergy had at least one major flaw. Regardless of whether there was a secondary or tertiary scheme put in place the trouble lies in the fact that the power is bottlenecked at the switchgear relays. As is demonstrated in the NOLA.com graphic, the electrical conductors between the switching cubicles (switchgear vault) and the dome itself carry the entire demand of the stadium. In theory there could be three, four, ten, or one hundred power lines (feeders) entering the equipment from Entergy's side. If there is a failure event in the switching device there will be power loss experienced in the dome. The design of the electrical system of the Superdome is not all that uncommon for a service that size. The conductors leaving the switchgear travel into the Superdome electrical room located inside the stadium itself. It is in that area where the schematics of the loading layout are determined. Much of the World War II Museum expansion currently under construction on Magazine St. and Andrew Higgins called for a branched 4160 volt electrical service where differing portions of the complex serviced from different high capacity conductors-isolating each of the portions from each other. Similarly, the standard design for office towers and high rise buildings segregate electrical load on secondary buss equipment (such as buss ducts) with different busses providing power for building facilities such as chillers and others providing power for office loading such as lighting and generalized small service demand for computers. If one of these busses were to experience a failure the others may remain in operation. Based on what I have read so far, my assessment would be that one of the feeders experienced an operating event. It is possible one of the feeders from the substation behind the dome experienced a surge of some type which cascaded downstream to the equipment. Once this voltage fluctuation reached the highly-sensitive relay electronics the switchgear relay simply operated as designed.