A specialist Ergon Energy team from Brisbane will travel to Cairns to try to get to the bottom of what has been causing a series of blackouts in recent weeks.

The team will conduct diagnostic testing of underground cables to assess what condition they’re in.

Tropical Coast area manager Mitch Wyper says local crews have already replaced faulty joints on some underground cables.

The underlying causes of those faults will now be investigated.

“We understand the concerns and frustration of customers and we sincerely apologise for the disruption to their businesses and the inconvenience caused by excavations in recent weeks to repair these faults,” Mr Wyper said.

“We do not consider the current standard of supply reliability in this area as acceptable.

“We’ve had a series of transition joint failures, which indicates a trend, but we haven’t confirmed whether it’s the result of environmental conditions, the increased load on the network at this time of year or a combination of those factors.

The results will determine the solution and Ergon Energy says there is potential for maintenance to reduce the risk of further outages.

It says it will notify customers of any planned work, and time the maintenance to minimise disruption to business owners and their patrons.