Just before 4am yesterday about 1100 customers were disconnected when equipment on a high voltage line failed on Fairy Street.

Powercor workers were able to restore all but 237 customers just before 7am, and soon had all services working but after reports of dim lights a second fault was identified on Merri Street.

The last restored customers were taken offline again while repairs took place, leaving many CBD businesses still without power until about 11.30am.

Some businesses and cafes put up signs saying they would close until the afternoon.

A Powercor spokesman said it was unclear whether the outage was caused by environmental factors or maintenance issues.

“We certainly apologise to everyone but we’re doing our best to get it back on as soon as possible,” he told The Standard.