More than 1,500 Nova Scotia Power customers in Halifax had electricity restored around noon but not before Dalhousie University cancelled some classes on its main campus.

Power has been restored to most buildings on the Studley and Carleton campuses, and the majority of buildings will reopen at 4:30 p.m. with the class schedule resuming at that time, said the university in a tweet.

However, some buildings still have no electricity. The Killam library, the chemistry building, Studley gym and the MacDonald building are still in the dark and remain closed. Dalhousie said it is working to restore power to those buildings as quickly as possible but they may not be open by this evening.

Power went out in the area around 9 a.m. The outage affected customers from the Armdale Roundabout to Dal's Studley campus.

Outages blamed on equipment failure

Maeghan Murphy, speaking for Nova Scotia Power, said the cause of the outage was equipment failure at the Armdale substation.

Keria Lum, who is working toward her master of business administration at Dalhousie, was in the Rowe building when the lights went out. Her class was part way through writing a midterm and she could smell burning plastic.

"I guess the power generator went on and then we heard kind of a popping sound — which was I guess what would be a fuse blowing — and smoke started to start and we all had to evacuate," she said.

"I think all of us are very stressed ... frustrated. A lot of people studied over the long weekend for Thanksgiving and didn't get to spend as much time with family and friends, and now we're either going to have to do a rewrite or we're going to have a heavier weight on the final."

More 1,500 customers are without power from the Armdale Roundabout to Dalhousie University. (Nova Scotia Power)

At about 10:15 a.m., Dalhousie said in a tweet that its Carleton campus had also lost power. All buildings on that campus, except for the Sir Charles Tupper building, were closed.

The Sexton campus remained open.