Shortly before 11:00 a.m. Friday morning, almost every cell phone on campus rang in unison. The call: a Yale ALERT.

In response to a widespread power outage Friday, the University used the Yale ALERT system to send out an automated emergency notification, the system’s first official use since it was unveiled in November 2007. Two phone calls, text messages and e-mails were sent to (though not necessarily received by) every member of the Yale community — the first told of the power outage; the second, sent approximately 45 minutes later, said the power would be restored shortly.

Reactions to the call were mixed. Some students complained that the messages did not provide any new information — they already knew the power was out when the first alert was sent and the power was back on by the time they received the second alert. The outage began around 9:40 a.m. Power was restored to the residential colleges and other affected buildings by noon.

“I thought it was kind of unnecessary,” Ming-Yee Lin ’10 said.

Maria Bouffard, the director of emergency management services, whose voice was on the phone messages, said a widespread power outage such as this is considered an emergency. Deputy University Secretary Martha Highsmith said ALERT phone calls, text messages and e-mails were sent out to all Yale affiliates because the outage was so widespread and affected many science labs.

Last March many science labs, as well as many University buildings, lost power for several hours because of an accident near the construction of Kroon Hall. Highsmith said that during debriefings after that outage, lab managers told her they needed more information about what was happening and how long the power would be out so they knew what to do with their specimens and chemicals that need to be refrigerated.

“We made a commitment at that time to let people know when the power was out and keep them updated on a time frame for it being restored,” Highsmith said.

After the alerts were sent Friday, Highsmith reiterated the University’s pledge not to use the ALERT system for routine announcements, saying care will be taken not to overuse the system.

Molecular, cellular and developmental biology professor Paul Forscher appreciated the ALERT.

“This outage was not long enough to cause significant damage in our area,” he said in an e-mail. “Had I been away from my lab and the outage longer, the Yale ALERT could have made a huge difference in protecting precious research materials.”

Grant Schafle ’11 also appreciated getting the ALERT, noting that “it is good to be informed.”

Jaya Wen ’12, who was stuck in an elevator between the third and fourth floors of Phelps Hall, said she did not receive any form of the ALERT until after firefighters rescued her, at which point she was already well aware the power was out.

In the course of a routine service check Friday, an electrician noticed a chafed wire in the central circuit breaker, Yale officials said. The power then had to be shut down so electricians could verify the problem and repair it.

“They did what they were supposed to do,” Director of Facilities Lou Annino said. “They’re supposed to fail-safe so no one gets hurt.”

It was not immediately clear who was responsible for maintaining the faulty equipment. Annino said it was the responsibility of United Illuminating Inc., a New Haven-based electricity provider. But a UI spokesman, Al Carbone, said the outage involved solely Yale personnel and equipment.

Carbone and Annino said Yale and UI coordinated their response and worked together to restore the system.