Contractor's 66,000 volt shocker

A contractor is "lucky to be alive" after accidently hitting a power cable with a jack hammer. Photo / Sarah Ivey

A contractor is "lucky to be alive" after accidently hitting a power cable with a jack hammer in south Christchurch yesterday afternoon.

Sydenham, Opawa, St Martins, Somerfield, Spreydon, Cashmere Hills and Hoon Hay all lost power after a 66,000 volt cable was severed at the Milton St zone substation by a contractor working on the water network.

Power was restored last night, however a severe strain has been placed on Orion's resources as other smaller cables are taking over from the damaged cable.

Orion chief executive Roger Sutton said the advisory to eastern suburb residents to cut back on power consumption now applies to southern residents too.

"It is a big cable," he said. "He is extremely lucky not to have killed himself."

Mr Sutton said the contractor drilled through a thick layer of concrete to reach the power cable, which has an oil line within it, and could have been "vaporised".

Mr Sutton said 99 per cent of the city has now had its power restored, although that does not include the CBD where about half of all properties remain without power.

Of those without power in the remainder of the city, the majority are in the eastern suburbs, around 1,000 customers.

"I've been to a few public meetings in the past few days and people get it - people understand that it has been an extremely unusual event."