The manufacturer of a protective device blamed in the power outage that interrupted the Super Bowl said a low ``trip setting'' on the equipment caused the partial blackout in the Superdome.

Friday's statement from S&C Electric Co. of Chicago said the outage would have been avoided if the operator of the relay device had set the trip threshold higher.

The statement did not name the operator, but the equipment was owned and installed by Entergy New Orleans, the local electric utility company that supplies power to the dome.

Earlier Friday, Entergy said the cause of the blackout was a faulty device that had been installed to prevent a failure of electric cables leading to the Superdome.

Officials say the device, called a relay, had been installed to protect the stadium from a cable failure between the company's incoming power line and lines that run into the stadium.

Company officials said the device performed without problem during January's Sugar Bowl and other earlier events.

They said the device has been removed and replacement equipment will be installed.

The power failure cut lights to about half of the stadium for 34 minutes, halting play between the Baltimore Ravens and the San Francisco 49ers.