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helicopter line inspector

Discussion in 'The Pub' at netrider.net.au started by jasonw, Feb 11, 2008.

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  2. I'd do that job.
     
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  3. Central Gippsland Institute of TAFE's Chadstone campus (the old SEC Linesman Training Centre) runs training in that. It's on an "as required" basis so you can't just enrol off the street - and needless to say very expensive. I used to know the instructors there.

    In practice the work is cheaper than using ground based crews. especially for hard-to-get-to areas. There's some interesting problems with it though - the arcing between the chopper and the wire is a bit interesting. Needless to say you've got to have a lot of confidence in the pilot.:LOL:

    It's not just used for inspection, maintenance and repair work is sometimes done from choppers as well.
     
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  4. Maintenance is often done this way, Tony. It saves having to take a line out of service, getting it earthed, moving in EWPs etc..

    Thing is, the electrical Code of Practice, often refered to in the industry as the Blue Book, has limits of approach for HV conductors. It's got me how they get around this, given that EMR is supposedly a hot topic.

    In any case, I'd rather be flying the helo than doing the work...
     
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  5. I was chatting to an old SEC guy who now works for one of the contract mobs about HV lines in the Alexandra pub a few years ago and he was a vertible mine of interesting info.

    Did you know the amount the cables sag between pylons on your typical 500kV line can vary by up to 2m depending on how hot the temperature of the day is and amount of current being pumped down the cables (causing them to heat up and stretch (sag) more).

    Telstra uses choppers to check optic fibre runs through the outback to find faults quicker than driving along a 1000km cable run (usually find a freshly plowed paddock or hole has dug up the cable which is easy to spot from above).
     
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  6. Im a newbie too this, but doesnt arcing only occur between Earthed Conductors. And seeing as a chopper isnt earthed why is there arcing?

    I think, though i maybe wrong the approach is only along the ground. Ie in a boom lift or what not, as there is a step potential around HV conductors. As you're in the air i dont think thats an issue. Again please feel free to correct me.
     
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  7. You could not pay me enough to do that job. There are so many things wrong with it on so many levels.
     
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  8. this is from the Q&A associated with that video:

    The helicopter is at earth potential when it leaves the ground. When it comes close to the power lines which are up to 500,000 Volt, the helicopter is still at earth potential. When the two come close enough together, the air between them will break down and equalize the potential between the helicopter and the wire. The bigger the helicopter, the more charge it will hold, and the bigger the arc between the two. The arc is constant as the worker holds out the discharging wand and contacts the wire. This is different from static electricity, where you get just one strike which instantly equalizes the charge. The reason is that the cable is A/C (Alternating Current). As the potential changes, the helicopter is charging and discharging 50/60 times a second all the time current is flowing.
     
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  9. :applause: I see thank you.
     
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