'Human error' could have left Rotorua in dark

A boat washed up on Pilot Bay beach in Tauranga. Picture / Alan Gibson

Transpower says human error may be responsible for a power cut that left half of Rotorua, including the CBD, without electricity yesterday.

About 12,000 businesses and homes were affected by the power cut, which happened after a substation on Transpower's national grid failed.

Elsewhere in the Bay of Plenty, high winds disrupted electricity supplies to nearly 3000 households in rural areas.

The outage in Rotorua for 40 minutes from 12.50pm disrupted traffic and businesses in the lunch-hour.

Transpower spokesman Chris Roberts said the cause was unknown but staff had been installing new equipment at a substation in Rotorua.

"Human error is one possibility," he said.

The power cut came a week after Auckland ground to a halt because of a fault at a Transpower substation.

Mr Roberts said the company regretted the latest incident but power cuts could not always be avoided.

"No one in the world has a perfect power system," he said.

Rotorua Hospital was forced to switch to a backup generator and was without its MRI machine last night.

The hospital had also restricted use of its CT scanner until the power supply was stable.

Spokeswoman Sue Wilkie said coupled with the junior doctors' strike, the outage had tested the hospital's contingency plans.

Rotorua District Council was able to keep wastewater stations going with backup systems, but spokesman Rex Moore said it might have run into trouble if the outage had lasted longer.

Wendy Roberts, manager of the Rotorua courthouse, said the cut disrupted proceedings for about 10 minutes before lunch.

The Fire Service responded to several calls when the outage triggered alarms, but was not required to rescue anyone trapped in lifts.

O'Malley's Irish Bar gained an extra customer when a man came in to get a beer after he was unable to fill his car at a gas station.

"He decided to fill himself instead," said publican Terry Meagher.

The BP station on Fairy Springs Rd sent about 50 customers to the BP in Ngongotaha.

Elsewhere in the Bay of Plenty, six power cuts caused by high winds affected 2800 rural households.

PowerCo network operations manager Ross Dixon said the faults were not related to the Rotorua outage.

The areas affected included Pongakawa, Aongatete and Te Puke.