KEY POINTS:
A blunder by a Vector technician who failed to spot a tripped switch is being blamed for the closure of a central Auckland school, which saw 2300 children sent home in the middle of the day.
By the time Mt Albert Grammar discovered the mains switch simply needed turning back on, all the students had left.
"It's a disaster really," said headmaster Dale Burden. "I'm not impressed."
Vector Energy is investigating how such a basic mistake happened - one of three investigations into power outages in Auckland in the space of 36 hours.
More than 430 homes and businesses in Papakura were without power for up to two hours yesterday morning after a contractor cut through a power line. The power company is likely to seek compensation from the third-party contractor after the outage at about 10am.
That cut followed one on Auckland's North Shore on Tuesday night, where hospitals, offices, shops, cinemas and more than 30,000 homes were left without power after an explosion in a substation in Wairau Rd at about 7.45pm.
Vector spokeswoman Philippa White said it could be "a day or two" before it was known what caused the explosion.
"But there's a chance that the evidence we need to discover the cause might have been blown up in the explosion."
In Papakura yesterday, traffic lights went out in the main streets and banks and shops were closed.
Jhinna Ali from Papakura Appliance and Things said his morning was ruined and he lost about $300.
Ms White said most customers had their power restored within 20 minutes, but 58 in the Wood St area had to wait until 12.40pm.
"We do generally put together a third party compensation claim when they cause outages," Ms White said.
"Third parties need to be responsible and make sure they are clear of underground cables. We have free maps available of our network so there's no reason why they shouldn't know where they are."
The power cut happened on a day when Auckland temperatures were down to about 11C.
Students from Mt Albert Grammar had to wait at the school for bus services to arrive early and take them home.
Power at the school failed about 9.30am. The Vector technician said the school could wait for the cables to be dug up and the fault found and fixed, or a generator could be supplied - at a cost of up to $2000 a day. Janine Wilson, the school's property manager, said a second team of Vector technicians arrived and were checking the power poles outside the school when one of them found the switch turned off.
Mr Burden said a vital half day's teaching and learning had been lost and "if it's because of a mistake then Vector may be in a bit of strife".
Ms White said Vector was investigating what had happened, but it appeared the technician made an assumption that it was a network issue based on the extent of the power outage.
"It's not an ideal situation," she said. "It's hard for me to imagine but that's why there needs to be an investigation."
Neville Simpson, chief executive of the Electrical Contractors' Association, said checking a tripped switch was "pretty basic, I would have thought".
"If you apply the same logic to your home, if the lights go out the first thing you do is check the mains switch."
