Technical issues at a Tauranga substation are being blamed for a large scale power outage.

About 930 properties in the Tauranga Central Business District went left in the dark following a brief power outage around 8am.

Powerco network operations manager Phil Marsh says the power cut was caused by a technical issue at its Hamilton St substation.

'We were able to restore supply within five minutes and investigations are continuing in to the cause of the fault.

'Powerco apologises for the inconvenience.”

Powerco is New Zealand's second largest electricity utility and largest gas distribution utility with around 442,000 consumers connected to its networks.

Powerco's electricity networks are in Western Bay of Plenty, Thames, Coromandel, Eastern and Southern Waikato, Taranaki, Whanganui, Rangitikei, Manawatu and the Wairarapa.

Its gas pipeline networks are in Taranaki, Hutt Valley, Porirua, Wellington, Horowhenua, Manawatu and Hawke's Bay.