A partial power outage during this year's Super Bowl occurred because a relay device with a design defect malfunctioned, an outside expert confirmed Thursday.
Entergy, which supplies electricity to the Superdome, and the stadium's management company hired forensic engineer John Palmer to perform an independent analysis of the Feb. 3 outage. Palmer is president of Palmer Engineering & Forensics in Kaysville, Utah.
Entergy has said it believed the outage was caused by an electrical relay device that it installed specifically to prevent a power failure at the dome.
Palmer's report says the primary cause of the disruption was a malfunction or "misoperation" of the relay.
The report also notes the relay had a design defect, and under testing it did not perform entirely as its instruction manual said it was supposed to. It says the factory default setting of the relay was inappropriate. Finally, it says there was "inadequate communication between the manufacturer and the utility."
Palmer said his findings are based on information available as of the date of the report. "If additional information becomes available that affects these opinions and conclusions, this engineer reserves the right to supplement this report," he wrote.
"We are pleased that Dr. Palmer's independent analysis has verified the root cause of the outage and confirmed that the relay operated in an unintended and unpredictable manner," said Charles Rice, president and CEO of Entergy New Orleans. "It has been our objective all along to identify the cause of the outage, learn from it, and prevent such an occurrence from happening again. The device has been permanently removed from service."