Marlborough Lines crews are investigating a power outage affecting central Blenheim.
A power outage affecting much of central Blenheim has been mostly restored, but lines workers are still mystified by what caused the outage.
Marlborough Lines was notified of the outage shortly before 10am on Thursday, with about 500 power users affected in the central Blenheim area.
People had wandered into the streets from darkened buildings on Henry St, Seymour St and Market St, and cafes were unable to use their coffee machines. However other sites on the same streets had been unaffected altogether by the outage.
Operations manager Warner Nichol said crews were able to restore power to most of the sites, but about 40 customers remained without power by 11.50am.
“We still haven’t located the cause of the fault, so we are working through the system progressively, and restoring power sequentially, isolating areas to determine where the fault is.”
It was possible some sites would experience further brief outages as a result, he said.
Lines workers had surveyed the streets for damage to power boxes perhaps from a car crash, but there were no visible signs of what had affected the power supply, Nichol said.
“We’re working with the underground network, not the overhead network … but we will be able to work through progressively to locate the section which is affected.”