Tiwai smelter power cut hits computer system

The Tiwai Pt aluminium smelter had a power cut for about two hours yesterday, affecting the computer systems on the site.

Smelter spokeswoman Andrea Carson said the plant experienced a computer systems failure at 5.30am yesterday, when an 11kV power cable failed, cutting all AC electricity on site.

Electricity was restored within two hours of the outage, she said.

"Power was restored, but staff were still trying to get some control systems up and running."

Plant duty manager Scott Westbury said the electricity cut resulted in "no measurable reduction in production".

Aluminium production remained unaffected as it utilised DC power.

Mr Westbury said staff were still working through some minor faults but no critical maintenance would be required.

Ms Carson said the worst affected area was Line 1, a pot reduction line, but no permanent damage to the line occurred.

The previous power failure at the smelter was in 2008 when a transformer failed and temporarily shut down a potline.

The damaged caused by the power cut in 2008 resulted in the plant reducing its production by 8500 tonnes a month.

The smelter uses 15 per cent of New Zealand's power supply and most of the electricity is generated by the Manapouri power station.

The Southland Times