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Power lines

Discussion in 'Electronics' started by Jose Luis Ocejo, Oct 29, 2012.

  1. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    I have a client that wants to do a shot straight down the middle of 2 large and tall power lines I scouted today and there is plenty of space between the towers and the cables the shot calls for a teen riding a bike along a wide path in the middle of the long row of power structures my question is, has anyone flown near power lines and had issues with the transmitter/receiver signals you can hear the the current of the power lines when standing near them
    thanks
     
  2. Guilherme Barbosa

    Guilherme Barbosa Distributor

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    did some photo inspection on 1300volts i think, Didn.t had a problem with 1,3 video link neither transmitter was using JR. Got pretty close like 6 meters away and yes was sweating on my underwear with the bzbzbzzzzzzzzz
     
  3. Arthur Vieira

    Arthur Vieira Flight Squad

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    I also did some flights near powerlines, not as near as Caju, more like 20m, but mine were the big ones coming directly from the electric substation of Itaipu Dam (Don't know the voltage)
    Radio (Spektrum DSMX) was OK, videolink was OK, flying was OK but of course I didn't use any coming home or carefree, fully manual flight and I did have some magnetic issues during flight. The CS during a forward flight lost it's path twice, noting serious, it was pointing forward and suddenly it turned like 20 degrees to one side. Easy corrected but with a 2 Axis gimbal, this can destroy the scene. Haven't tried the Radian, but there shouldn't have any issues.
    Please post the results here after the flight.

    Good flight.
     
  4. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Arthur: if they were primary transmission lines, my guess would be 340 - 400 Kilovolts. But just a guess.
    Definitely not to be fooled with....

    Andy.
     
  5. Josh Lambeth

    Josh Lambeth Well-Known Member

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    You should call up Quadrocopter and ask them what happens to a copter when it gets in high-voltage lines... they said they had one hit and it ended up shorting out and melted the whole copter!!!

    Josh
     
  6. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Ah yes, the new models, the Cineflash and the Cinetoast.

    Andy.
     
  7. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    Ok enough of the funny stuff so in the event that no cables are touch........at this point my understanding is that perhaps only the GPS could get disrupted but the RC transmitters and the video links are ok .....right??
    like I said the shot calls for a strait path above the towers along the dirt road looking 3/4 down then descending following a kid on a bike
    here is a picture of the propose site

    IMG_1265.jpg
     
  8. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    JLO, those look like pretty high voltage (multi-kilovolt) lines. They almost certainly will induce some stray voltages in electronics. They will also be emitting fairly strong radio frequency interference (hence interfering with GPS) and I suspect they might be carrying enough current to create EMI, electromagnetic interference, that will upset the compass.

    Altitude hold should still work as that's based on the pressure transducer, but don't plan on flying anything but manual control.

    Each of the three phases is carried on a separate wire, so you cannot actually short the line out -- the lines are too far apart.

    That said, can you find out whether the topmost line for each of the three wires is energized -- is it an insulated support line or part of the transmission line?

    However, you could perhaps short out a line to a tower. Carbon fiber is conductive, so you can expect, in the event that happens, a bright flash, and no Cinestar left to speak of. Oh, and a bill from the power company....

    If you can stay away from the towers, even if you clip a wire, you might crash, but you won't burn -- other than from a LiPo impact fire.

    Can you manage the client's expectations so that you can do some experimental test flights directly underneath the power lines (where the inductive effects are at their worst) but without going to close to them, just to test the Cinestar's behavior without being too far from the ground?

    Hope this helps
    Andy.
     
  9. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    Thanks Andy at this point I am getting second thoughts its a cool shot very graphic that ONLY a RC craft could do, a full size would not even consider doing some thing like this, the plan was to stay smack in the middle but in the event of a mishap the negative consequences are very hi, a mishap could easily come from the potential interference from the lines I have already brought up the concern with the client and he has a second option location for the shot, and that is the kid riding on a side path along a railroad track so I am not going to risk it too bad it would have look great on the reel
     
  10. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    Actually they do use full size choppers for power line inspections and repair. The chopper hovers so close to an energized power line that the lineman draws a spark from the line several inches long as he clamps a conductor onto the line -- that brings the chopper up to the same potential as the line and renders it safe for the lineman to work on the line.

    Check out the video at http://www.haverfield.com/employment/ and the still image on that page. Those guys don't have to be crazy, but it might help.

    But, I'm with you -- trust your instincts -- they are more likely to be right than wrong -- and it's your aircraft after all, so you as the pilot have the ultimate responsibility. And the ultimate decision.

    Andy.
     
  11. Jose Luis Ocejo

    Jose Luis Ocejo Active Member

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    You are right my point was that a regular Heli would not risk flying so close to power lines specially trough the middle for filming purposes where the only way out is up or down, I am going to scrap the location too much risk for a shot, this remind me of this video:

    we should start a thread about this topic "When to say NO"
    it remind us of the fine line of taking some risks vs to playing it too safe, and to realize of the big damage we could cause with our cool machines in this case this guys where very lucky no one got hurt
     
    AirRaid likes this.
  12. Andy Johnson-Laird

    Andy Johnson-Laird Administrator
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    I think you, quite rightly, did just start a thread about when to say no -- but feel free to start another one with that topic.

    I think we'd all benefit from knowing what NOT to do, where NOT to fly, and when to say NO.

    Andy.
     

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