Fault found but power could fail again

Many Far North businesses, including BP Kerikeri, closed during the power outage.

Mid and Far North residents are being warned that the power could go out again this afternoon while repairs are carried out to Kaikohe substation

Lines company Top Energy believes it has found the cause of Friday's massive power outage - but is warning people in the Mid and Far North the power could go out again while repairs are carried out.

The power cut affected about 30,000 households and businesses from Towai to Cape Reinga and started about 10.30am.

Power was restored to the main towns around 1.30pm but some outlying areas had to wait until 4pm.

On Friday helicopters were used to search the power lines around Kaikohe substation but found no obvious signs of a fault.

Today engineers found what they believe is the cause, a broken insulator inside the substation.

The company is trying to fix the equipment this afternoon without disrupting power supplies but warns a second outage could occur, again affecting the entire Mid and Far North, if the insulator fails again.

Photos from Friday's power cut:

Image 1 of 8: BP Kerikeri closed during the power outage.