Fieldlines.com: The Otherpower discussion board
Homebrewed Electricity => Wind => Topic started by: Cary on October 10, 2010, 11:09:20 PM
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can a wind generator run with the pole / mast being ground (-) and the positive(+) be the only wire ran down inside the pole
just generator on pole all other including diode will be at bottom of pole..
not cheaping out just trying to go with simplicity have searched and looked at many pics online and cant tell if all are using 2 wires or not..
any help explaining this would be great.
as well any users in Regina sask area that still exist using wind .. would love to be able to see someones setup ..first hand..
online leaves way to many questions..
thanks for any help..
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Yes, in theory. But it isn't a good idea. Touching the pole could result in electrocution. Turbines, even with rectifiers produce a choppy wave that is basically a form of a/c. Even low voltage a/c can be lethal.
You would also have to isolate the guy wires from ground like an AM radio tower to avoid shorting the output.
If you can afford one wire, you can afford 2.
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that's all i needed to toss that theory out.... 2 wires it is...
thanks for the explanation..
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Welcome to the forum, Cary.
Another important factor in grounding the tower to earth is that this becomes the pathway to ground for lightning, and for some electrical faults. With a separate conductor to ground, one that doesn't normally carry current, your batteries aren't directly implicated in these problems, saving them from potential damage. So in addition to the 2 wires for the power, a grounding rod is a very good idea.
(Is Calgary close enough to you? ;) )
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If the unit is dc or if you rectify up the tower and run dc down then you could use the tower as a return and ground it but still not a good idea as the tower may not be a good conductor with many joins and if you plan to use the yaw bearing as one connection then again that is not without problems.
Not worth the tiny saving in a length of wire.
Flux
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its funny getting the lightning notes as it was my c band satellite pole ( 25 ft up 8 down)
on top of my garage for the last 15 or so years and no lightning and its the tallest point on the block..
it will be (for now) a dc pma generator on it.. but i have wired it 2 wire..
thanks for the info on the wiring.. all i have to change now is i have standard lead acid truck batteries.
.(make do with what you have) trying to find better replacements.
thanks again hope i have mine generator up this weekend.. all assembled.. just need to put up on pole and hook up shut off and load to test
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Hi
You say the tower is on top of your garage. You are going to get a lot more vibration from a wind turbine than a satellite dish, even one as big as a C band dish. Are the guy cables secure enough and not just on a bolt into the top of the wall.
Brian
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i originally welded braces that are bolted to the roof ( properly braced into structure)
the dish was up 20 ft and i have open field behind me so we made it strong
its drilling pipe welded together to spec..
i put the generator up today.. watched it spin around a bit.. pole is definitely good enough till i go higher.. ;)
the shut off gave me worries.. i put in switch checked on ground.. switch worked..
put on to generator motor winds are only 12 -20km/h and it would not stop the generator blades still spin just slower.
load, regulator and batteries are all hooked up(tried all off too no difference)
thinking i should go with a proper furling system as this gave me worries
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Don't use a brake switch on a dc motor for anything other than parking. never try to stop it when running, they just won't stand that sort of treatment.
Flux
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thats what i was using it for
blades were hand spun ( 2 finger no force) and it couldnt hold them stopped..
am dissassembling to change the furling.. sad as its a nice windy day to test.
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Hi Cary
I'm in Regina too. Might be I'm the closest. We Might meet one day.
Ron
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Using a separate return for ground isn't going to help for lightning protection in the slightest, if the tower is solid electrically speaking no reason not to stick the diodes right next to the alternator.
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thats exactly the thought i had its dc. go one wire..
since then i have run 2 wires now
tested day one.. worked ok.
blades were to long ( fluttered and forced furl in too light wind )
could only generate 4 volts before a furl..
shortened blades from 36 to 26 (inches) worked way nicer but need some furling now
as itll spin up fast
using 1.5 inch square tube need some kind of hinge for it that will take the abuse of the wind.
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Do NOT put current through a bearing. The lubrication and intermittent metal-to-metal contact produces the equivalent of electrodynamic machining, which removes metal from the bearing surfaces and suspends it as metal dust in the lubricant, rapidly destroying the bearing.
(This effect was discovered when a Russian engineer tried to cool the points on a gasoline engine ignition system by immersing them in oil - and found the points, instead of being protected, were eroded to nothing within a week.)
If you're going to use the mast as a conductor you'll need to provide a brush and slip ring, and insulate the bearing on one side. (At that point you might as well use TWO slip rings and skip using the mast as a conductor, with all the other problems that might cause, such as rapid electrolytic corrosion at the joints once they get wet and ordinary corrosion makes them resistive.)
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is there a camera on my yard.. :D
i never mentiond how i've mounted everything ( funny)
mounted the generator assembly on a chevy front disk brake assembly,
figured it could use a few more mile on it..as its a real tough yaw bearing idea.
will post pics in diary soon
sacrifice wires down pole though
and after talking on here
\ i figured the bearings would pit from the electricity going through it.so i nixed that idea fast.
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electricity through ball bearings should be the first laboratory experiment in any EDM course...
for cheap entertainment, google "ball bearing motor"...
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for cheap entertainment, google "ball bearing motor"...
Note that the ball bearing motors are unlubricated. The EDM effect occurs when the current must spark through a dielectric liquid such as oil or water. Works as follows:
- Heat of the spark opens (or holds open) a channel through the liquid, while the end of the spark (especially at the positive terminal) melts a tiny pool in the metal.
- When the spark stops the channel collapses, creating a shock wave that blasts the tiny bit of molten metal out of the pool and quenches it rapidly, leaving a fine dust in the dielectric liquid.
Repeat a few thousand times per second and you rapidly and selectively machine the metal into the dielectric liquid. A machine tool will pump the dirty liquid away and replace it with fresh/filtered liquid. In an accidental EDM situation in a lubricated bearing the lube becomes gritty and starts eroding the bearing mechanically as well.
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Not to steal the thread, but a question for ULR. I don't doubt what you are saying about contacts, as I've ruined many point sets with a bit of oil.
My question is how do they get away with it in oil filled pumps? Had a couple apart lately, (septic tank problems) and they have the regular start
winding with contacts. And filled with oil. Baffled me when I saw it.
Just curious.
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Not to steal the thread, but a question for ULR. I don't doubt what you are saying about contacts, as I've ruined many point sets with a bit of oil.
My question is how do they get away with it in oil filled pumps? Had a couple apart lately, (septic tank problems) and they have the regular start
winding with contacts. And filled with oil. Baffled me when I saw it.
Just curious.
At a guess: They only operate once per startup. So it takes a long time to burn away enough of the points as microscopic bits of dust to affect the operation.
Points operate at RPM * cylinders / 2 times per minute. So a week of operation at 1000 RPM on a four-cylinder engine is over 5 million cycles. How many years does that work out to for the start contacts on a pump motor?
Similarly, a bearing carrying current breaks the current some large number of times per revolution. While this arcing is spread out over the race, it's still about #-of-balls sparks per revolution for each spot on the main ball-contract tracks.
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I'm in Swift Current.
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I think it is just a lifetime cycle.
High voltage switchgear is often oil filled. The oil quenches the arc vetry quickly. Without the oil you need air blast or magnetic blowouts to clear the arc.
Those oil breakers have massive contacts and during the whole of their life the number of breaks are really quite small. Possibly another factor is that they have soft contacts and the harder materials seem to be eroded more rapidly.
I assume the small contacts in oil filled pumps similarly have a satisfactory life for the number of cycles they perform, even in air contactor contacts erode but they manage a few thousand cycles and that is a long working life.
Flux
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Now that I have taken up some of someone elses post, thanks ULR, and Flux. The thing that confused me was, the contacts were in fine shape,
and pump was approx 9 years young. And yes, very soft contact material.
Thanks again