The failure of a newly installed connector appears to have been the cause of two fires in Kawakawa - one of them in a shed packed with fireworks and cyanide - and a two-hour blackout in Russell on New Year's Eve.
About 9.30pm on December 31 an 11,000 volt overhead cable dropped on to a property at Kawakawa's Paihia Rd, electrifying a shed containing up to 300kg of fireworks belonging to possum trapper and Guy Fawkes retailer Hadyn Wills.
The shed also contained the possum poison cyanide so the blaze sparked a major emergency response, with firefighters and hazardous materials experts coming from as far away as Whangarei.
The falling line also cut power to Russell for two hours during New Year's Eve celebrations and the resulting power spike started a second fire in a house about 200m from the burning shed.
Top Energy chief executive Russell Shaw said the company's investigation could not be completed until Fire Service reports into the two fires were finished, but a draft report had been prepared for the company's insurers to minimise delays for the affected home owners.
It found that a recently installed mid-span compression joint connecting two lengths of cable had failed. The joint had been installed properly so Top Energy was now following up with the manufacturer to find out why it had failed, Mr Shaw said. Hundreds of the connectors were in use around the district without problem.
The failure was a case of "Sod's Law", he said. The new connector had been installed to minimise power outages when the line is put underground in the next 12 months - but had ended up causing a two-hour power cut in Russell on New Year's Eve. "It was done with the best of intentions but the outage happened on the worst of evenings."
Both Kawakawa properties were insured. The cost of repairs to both properties and temporary accommodation for the family with the damaged home is expected to be covered by Top Energy's insurer.