"Delta should have had an effective policy in place that required the worker to eliminate the risk of such an incident. In this case, that would have meant disconnecting the power completely at the road," WorkSafe chief Inspector Keith Stewart said.
"None of Delta's written policies specifically required elimination, nor any explanation of how the hazard could have been eliminated.
"Elimination of any hazard at work is always preferable to isolating it and Delta could have prevented this unfortunate incident if it had provided written guidance on how to eliminate the risk of low voltage arcing," Mr Stewart said.
Delta was fined $35,000 and ordered to pay reparation of $49,600.