According to business association Heart of the City, the cuts had a "significant impact" and businesses will have lost thousands of dollars.
"There will be consequential impacts as well that certainly add up for small businesses that are trading and reliant obviously on electricity," its chief executive Viv Beck said.
Jordan Baker who works at the restaurant chain Better Burger said they lost power twice on Thursday and were forced to cancel two orders.
"The telephone didn't work so for security reasons I just shut the shop, had my lunch, and when the power came on I opened the doors again," said Mary, who works at a shoe store in Britomart.
The McDonald's restaurant at Britomart was also affected by the outage.
The restaurant manager said the three-hour outage would mean a hefty loss.
"We are in the busy lunch rush, it was about 12.20[pm] or 12.25 and then all of a sudden the power goes.
"We decided to close the restaurant and give full refunds to the customers, and then we asked if they want to sit in the lobby or stand outside for a while until we sorted out the issue, what the reason is.
"Then I checked with our other restaurant, the East Street McDonald's, they also don't have power.
"Still the issue is not fixed because we have our internal system is crashed ... because of the sudden power cut. So they are still working on it, to fix the menu boards, fix the kiosk ...
"All the machines are off ... we have to redo the food safety check before we open and serve to the customers, so it's critical, that's why we are taking time so everything we are serving to the customer is safe.
He said they could not ask staff to go home or go on break either, and the food would be going to waste.
Power was fully restored by 2pm, according to Vector.
- RNZ
