The Glendale Community College campus on Verdugo Road was closed Wednesday.

The Glendale Community College campus on Verdugo Road was closed Wednesday. (Raul Roa/Staff photographer / December 6, 2012)

A failed relay unit located near a main transformer is to blame for knocking out the power at Glendale Community College on two separate days over a weeklong period, official said Thursday.

Electricians were able to repair the equipment Wednesday night after power outages forced administrators to close the campus Nov. 30 and Dec. 5.

After turning students away on Wednesday, school resumed Thursday morning after electricians brought the power back after 8 p.m. Wednesday night.

“It was very hard to detect,” said Interim Supt. Jim Riggs.

Electricians replaced the unit, Riggs said, but the campus planned to keep emergency generators it hauled in this week as a precaution through Friday.

“The campus is back buzzing,” he said.