500 kV FLASHOVER

September 30 2004, 5:30AM
Flashover on a 500 kV line.
Line could not be re-energized until repairs were made.
Line was out of service for nine hours.
A rough estimate for the nine hour outage: $200,000-$400,000

Reasons for the flashover:

• Dust contamination from rock crushing operation.
• Exceptionally dry year due to 180 days without rain.

Click play to start | Click here if clip doesn't start	Flashover buildup on 500 kV line Video demonstration

We were asked to fly a portion of this 83 mile line to determine if we had any other contamination problems.
We easily identified four towers that needed cleaning.
Bird contamination was also building on the insulators.
Helicopter cost for the one hour flight, $550.00

176 towers were inspected in a one hour flight.
Four towers had extreme corona activity
Two of those towers needed to be hand wiped.

Click play to start | Click here if clip doesn't start	Before & after treatment: The airborne inspection of the 500 kV line using the DayCor gimbaled unit Video demonstration

Conclusion:

• The Corona camera easily identified contamination which allowed us to more effectively use our resources.
  
  
• The Polytech Gimbal used on our helicopter is a quick and efficient way to patrol our bulk transmission system.

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Insulators hand cleaning