Richard Healey

post on Facebook

Monday 31 August 2020

Last Thursday a contractor on the Aurora network brought an isolated and earthed Aurora line into contact with a 33,000V line owned by Talla Burn generation livening up three trucks, the 11kV line and the consumer fusing.

Near miss is not an adequate phrase to cover this event. The images are some of the burn marks left by truck tires as the 19,000V traveling through the lines overcame the impedance of the tires to track to earth.

In the last couple of days Aurora have confirmed that:

1; They HAD NOT TOLD TALLA BURN that they were undertaking work close to their lines

2; After their line had caused the Talla Burn line to trip, they contacted Talla Burn to tell them the breaker connecting them to the network had opened - but STILL DID NOT TELL THEM THAT THEY HAD A CREW WORKING NEAR THEIR LINE.

3; The first contact from Aurora System Control to Talla Burn confirming that an incident involving an Aurora contractor took MORE THAN 40 MINUTES.

For people not involved in the electricity supply industry I should point out that knowing who is working near your lines is a fundamentally important element in ensuring the safety of those workers. You absolutely need to know that workers are present to avoid turning the power back on and getting them a second time.

Talla Burn confirm that they have operational control of the line and could have relivened at any moment after the first trip. Thank god Talla Burn do not have auto-reclose configured on the line. If that had been an Aurora line the chances that they would have reclosed it are very high indeed. That would have resulted in the worksite, once again, instantly reaching lethal voltage.

What Aurora HAVEN'T SAID is that 22 minutes after the fault Talla Burn discovered the fault themselves while patrolling the line. The dozen or so linemen standing around the worksite were a pretty good clue. Tallaburn rang Aurora GM of operations John Campbell - to be told that he knew about the location of fault and the presence of an Aurora contractor - but hadn't passed that knowledge on to Talla Burn, THE PEOPLE WHO OWNED THE LINE AND HAD OPERATIONAL CONTROL!

Just to underscore how good the communication skills of this "open and honest" company really are, Aurora then gave another contractor ( sister company Delta) the task of downloading data about the fault from the Talla Burn relays. Delta approached the independent engineer who had set up the protection and asked him to supply the data - WITHOUT SEEKING THE PERMISSION OF THE ASSET OWNER.

The engineer, quite rightly, referred them to Talla Burn - who refused the request while they do their own investigation.

In a stunning effort to confirm that they share Aurora's communication skills, contractor Connetics DID NOT inform Talla Burn that they were working near their lines, DID NOT inform Talla Burn when they contacted their lines and caused the fault and HAVE NOT contacted Talla Burn to this day to explain what happened, ask what damage they caused and - most importantly of all - discuss how this could be avoided!

Some other important information has surfaced about the fault in the last day. Watch this space.