A major 55-minute power outage along the Central O'ahu corridor last night affected 27,000 Hawaiian Electric Co. customers.

HECO spokesman Darren Pai said power was restored to all customers at 7:45 p.m. The outage, reported at 6:50 p.m., was concentrated in the Pearl City area but affected customers in pockets of 'Aiea to the east, westward in Waipahu and north to Mililani.

Transmission equipment problems at the Waiau plant caused the outage, Pai said.