Powerco says substation may have caused surge

Powerco has admitted one of their substations might be the cause of an electrical surge that cooked phones, erased fax memories and knocked out broadband services in Carterton last Saturday night.
Carterton couple Neil and Aurea Hickland live 500m from the substation, on the corner of Somerset Road and State Highway 2, and believe the surge, which happened around 10.30pm January 26, was responsible for frying their cordless phone and scorching an exterior phone port.
At around that time the Hicklands' neighbour on Somerset Road, Robyn MacGregor, heard the explosion.
"It was around 10.45 and I'd just hopped into bed and heard a hell of an explosion. It was an electrical- sounding one. Then I saw a flash of light like forked lightening, it lit up the bedroom," Mrs MacGregor said.
She said her house, 200m from the substation, was built four years ago with a power suppressor like the one installed in the Hickland's home on Monday, which cost Telecom $2500.
"The flash could have come from the substation but my concern is that it could have been the power suppressor in my house."
Since the incident she said she had contacted both Powerco and Telecom and both had given her a lukewarm response.
"I've rung both Telecom and Powerco and they both seem disinterested," she said.
Carterton couple Richard and Davinia Schofield live 4km from the substation on Hughes Line and believe they were also affected by Saturday night's power surge, losing two cordless phones, two network phones and half the memory on their fax machine in the process.
"I heard the phones go 'ding' just when the power went off," Mrs Schofield said.
"Luckily the phone wasn't connected to Sky because then we probably would have lost that too," Mrs Schofield said.
The surge also affected residents in Neich's Lane about 1km from the substation.
The Hicklands have been plagued with problems ever since they bought their home 11 years ago. In that time they say they have laid to rest five phones.
Various technicians from Telecom and its subcontractors told the Hicklands the surges were caused because the substation creates an Earth Potential Rise (EPR), which appears to have affected phone and power lines in at least a 4km radius around the Somerset Road substation.
Powerco issued a statement on Friday after the Hicklands' story appeared in the Times-Age on Thursday, which said the company have "commissioned an investigation into claims made by telecommunications contractors that problems with a person's telephone in Carterton may be related to a Powerco substation nearby".
Powerco network operations manager Ross Dixon said the company only became aware of the claims after being contacted by the news media this week.
"Powerco is aware that EPR (earth potential rise) near electricity substations can in some instances cause interference with
telecommunications infrastructure and in general the telecommunication network provider builds protection into its system to reduce the risk of this occurring," Mr Dixon said.
"Powerco will work with the telecommunication network provider to investigate the problem on their network, determine the exact cause of the problem and if it is related to Powerco's operations we will work with them to develop an appropriate solution."
Telecom also issued a statement through spokesman Brett Jackson addressing resident's concerns.
"Although the Telecom network is built to be very reliable, damage to Telecom equipment and customer equipment like portable phones, faxes and modems may be occasionally caused by external sources such as lightning strikes or power surges," Mr Jackson said.
"Power substations have a radius within which electrical voltage may stress cables (termed earth potential rise) and this can potentially damage equipment or interfere with phone lines. The size of an EPR area varies according to factors such as soil resistivity and the earth grid resistance beneath the substation. From time to time, an EPR area may change without Telecom's knowledge.
"Telecom's exchanges are fitted with devices that protect against electrical surges and we also install isolation devices in customers' premises where we are aware that they are affected by an EPR area. These devices eliminate the chances of an electrical surge affecting the customer's equipment. Standard phones (ie phones which do not rely on mains power) are not affected by electrical surges," he said.
"We'll be working with the local power supplier to assess whether the EPR area for this substation has changed and whether customers have been affected."