Around 1000 households in the western suburbs of Rotorua experienced power losses tonight after a jumper failed.
Danny Gough, from Unison, said around 4.45pm there was a device failure on one of the major sectors supplying the Fairy Springs area.
He said the failure meant that some households close to the site lost all power, while most affected households had "part power".
"It meant we couldn't maintain normal levels of voltage to 1000 customers," Mr Gough said.
"Everything was back to normal in about an hour."