BANGOR, Maine — Most of downtown lost power for about 90 minutes during lunchtime on Wednesday.

Beginning at about 12:50 p.m., the power went out for about 315 Emera Maine customers along parts of Main, Exchange, Hammond, Columbia and Harlow streets, among other downtown streets.

The Bangor Fire Department issued a tweet to drivers to take precautions as the traffic lights were not working at the intersection of Main, Hammond and State streets, as well as the intersection of Broad and Main streets.

Temporary stop signs were set up, drivers slowed down, and there were no accidents reported before the lights were restored at about 2 p.m. An estimated 129 customers, mostly on Columbia Street, still remained affected at that time, but all power was restored between 2:30 and 3 p.m.

The outage was caused when a piece of safety equipment that cuts power off when there is a surge — to prevent appliances and equipment in homes and businesses from being damaged — was tripped, according to Allison Doughty, manager of communications and marketing at Emera.

“We’re not sure what tripped it yet, but it needed to be repaired,” Doughty said. “A squirrel, bird, or branch could have contacted a line and caused it, but if we’re not there to see it, we don’t always find out what caused it.”

At about 1:30 p.m., Megan Ring, a server at Paddy Murphy’s at 26 Main St., said all the kitchen equipment was shut down, but restaurant workers were taking cash for cold sandwiches and drinks. She said they also were offering hand-written receipts.

“It’s not great,” Ring said. “We’re managing, but obviously, if it lasts too long, we are going to start getting worried.”

Niles Parker, executive director of the Maine Discovery Museum at 74 Main St., said at about 1:30 p.m. that the pump for the salt water fish tank shut off causing water to overflow onto the floor. The fish were OK, but it caused a bit of a mess.

He too was worried about how long the outage might last. If it lasted into the evening, he said, staffers were likely going to have to take some fish and animals home overnight to keep them out of the cold.

Parker also felt bad that he had to turn away three families, including a young child who was looking to celebrate his birthday.

BDN writer Danielle McLean contributed to this report.