Transpower is undertaking further investigations into Monday's power outage across the central North Island.
More than 4000 properties in Raetihi, Taihape, Ohakune, National Park and Ongarue lost power due to a fault around 9am.
Transpower spokesman Geoff Wishart said there was a tripping (fault) on a 110,000 volt line feeding areas between Ongarue in the north and Taihape in the south.
"Normally, these areas are fed from the south, but because we had this line out for maintenance, they were being fed from the north."
The northern part of the line tripped around 9am.