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Help needed with static electricity!

  1. Sep 11, 2011 #1
    I have a problem that is costing me lots of $'s. I built a pole barn seven years ago that is about 50 feet from my house and garage. I am on my third garage door opener due to logic boards being destroyed by static electricity. I have had a second electrician check out my wiring and he says he can't find anything wrong. We did add a ground for the pole barn where before it was grounded through the house where the power originates. I have a surge protector on the garage door opener itself. These are Chamberlain garage door openers sold by Sears. All have been the same model since I had to add a extension for the rail because of the oversize door. It's the only model that Sears sells that will use an extension. I have been told by Sears / Chamberlain that static electricity is the problem and the logic boards are susceptible to static electricity. All of the problems have been after electrical storms. I have never had a direct hit to the barn or house. ( Knock on wood!!!)

    I am trying to come up with a way to arrest the static electricity. My thought is if I ran some light wire around the top of the barn above the garage door opener and connected it to the direct ground wire that I had installed that this would be the best attraction for the static electricity. My concern is that I don't want to create an attraction for a direct lightning strike.

    Before you give me your lofty answers let me tell you I know about as much about electricity as I know about quantum physics or women or ..... well you get it, I'm an idiot about electric. So please explain to me like you would to let's say a Cocker Spaniel.

    Thanks!

    Bill
     
  2. jcsd
  3. Sep 11, 2011 #2

    dlgoff

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    Welcome to PF WHS SHOCKED.

    What type of roof does your pole barn have? If it's a corrugated steel one, you could put up a lightning rod connected to it.
     
  4. Sep 11, 2011 #3
    It has an asphalt shingle roof and vinyl siding. All wood framing.
     
  5. Sep 11, 2011 #4

    dlgoff

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    Well, my parents house has a lightning rod on the composite shingle roof and the house has never "attracted" lightning. It has a steel cable leading to a ground rod.

    If you do put up one, the ground must be very good (depends on soil condition and how well the ground rod contacts the earth).

    433px-Lightning-rod-diagram.svg.png

    http://en.wikipedia.org/wiki/Lightning_rod" [Broken]
     
    Last edited by a moderator: May 5, 2017
  6. Sep 11, 2011 #5
    Would a lightning rod on the outside of the barn arrest static electricity on the inside of the barn? There are no signs that the barn has ever been hit by lighting. Just static electricity caused by lighting???

    Thanks for the reply.
     
  7. Sep 11, 2011 #6

    dlgoff

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    The idea is, the static build-up on the building would be shunted to ground preventing discharge surges which may be what's killing your electronics. A lightning strike isn't necessary to get discharges. From the wiki link:

     
  8. Sep 11, 2011 #7
    Ok now. Please remember to explain like you would to a Cocker Spaniel.

    Are you saying yes, a lightning rod would get rid of static electricity inside the barn? If this is correct then why wouldn't a wire inside the barn attached to my ground wire do the same thing?
     
  9. Sep 11, 2011 #8

    dlgoff

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    Cocker Spaniel? Nope. :wink:

    Yes. The charge build-up will accumulate on the building with the highest charge on the roof. So the lightning rod should discharge (equalize the charge with earth over time) of the whole building. Check out this explanation of how the charge builds up. i.e. how positive and negative charge build-up.

    http://hyperphysics.phy-astr.gsu.edu/hbase/electric/lightning.html

    From this animation, you can see that you don't have to have a direct strike to [STRIKE]be[/STRIKE] have discharges that can cause electronic component damage.

    Leaderlightnig.gif
     
    Last edited by a moderator: Apr 16, 2017
  10. Sep 11, 2011 #9
    So why wouldn't my inside "do-it-myself" system work? Does the suppression have to be on the outside of the building roof?
     
  11. Sep 11, 2011 #10

    dlgoff

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    This would be best; where the charge density is largest.
     
  12. Sep 11, 2011 #11
    Would my system be better than nothing at all? Would it possibly create any more problems like attracting static electricity?
     
  13. Sep 11, 2011 #12

    dlgoff

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    Without seeing your system (which doesn't sound like it would do too much), it would be hard to tell. As far as "attracting" static electricity; probably not.

    Why not just put up a simple/cheap rod on the highest point of the roof? You must consider the cost between installing a lightning rod/ w good ground and the cost of replacing the electronics.
     
  14. Sep 11, 2011 #13
    Well beside being an electrical idiot, I'm cheap!!

    But replacing Garage Door Openers isn't cheap either so I am going to have to do something. Are there systems for "do it yourselfers" out there? Or is this something that is best left to the pros?

    Thanks for your indulgence with me. I appreciate it much.
     
  15. Sep 11, 2011 #14

    dlgoff

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    There are DIY lighting protection suppliers. For example (note: I'm not endorsing any particular supplier. I just googled.):

    http://www.lightningrod.com/"
     
    Last edited by a moderator: Apr 26, 2017
  16. Sep 11, 2011 #15
    What does this mean? "extension"?? How does the wiring get from your house to the barn? Above ground or buried? Even buried cable can require lightning protection. Power and communications companies do that all the time on their underground and sometimes above ground cables.

    If lightning caused the problem, "static electricity" is hardly the issue unless you mean
    "lightning". Try talking with someone else at Chamberlain..you might get a different answer.

    Exactly how was the barn wiring "grounded" at the barn. What wires were connected to ground? Is the wiring from the house to barn "grounded"...a three wire cable for 120 volts, with a bare wire??

    Are you positive your house is properly grounded??

    Was this inspected and approved? If not, find out how it was grounded and go down to you electrical inspectors office and ask how it should be done.

    You should to talk with someone who is expert in (practical) grounding issues not a run of the mill electrician who likely does not understand all the issues.
     
  17. Sep 11, 2011 #16

    dlgoff

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    I'm fairly sure he means a mechanical extension of the door hanger.

     
  18. Sep 11, 2011 #17
    Thanks
     
  19. Sep 11, 2011 #18

    jim hardy

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    Is the circuit board inside a metal box?
    Is the metal box connected to the green (or bare) wire that goes back to earth somewhere, hopefully to panel in your house??

    Take your voltmeter and check voltage from black wire to that green (or bare) wire
    you should get 115 volts or whatever the electric co is delivering you that day
    and you should read exactly same between black and white wires.
    If not, something is not right in your wiring out to the opener..

    next take your 75 ft extension cord .
    Plug it into a good outlet in your house and carry the other end out next to your garage door opener.

    Using your multimeter on lowest ohms scale,
    read the ohms between your garage door opener frame and the round safety contact hole in your extension cord plug. You may have to insert a nail or something to get contact there.
    If it's more than an ohm or so find and fix the bad connection.
    Now you've verified that you have a decent earth ground at your door opener -

    is the circuit board protected from electric field ?
    If it's inside a metal cover that's grounded (i prefer term "earthed"), that should do the job.
    If the cover is plastic, well, get your pop-riveter and some aluminum flashing and give it a metal skin, and earth that with a screw to the frame or a short ground wire to a nearby frame screw.

    I once had a Sears water softener that was sensitive to the power surges that come in when lightning strikes power line. You said you had a surge protector on the opener - close to the opener i assume.
    it is important that the surge protector have good connection to earth. Hence those first checks. Your wire to earth should be about as large as the conductors,
    and run directly without splices.
    Lastly routing is important. The earth wire should be run physically with the other two wires to make a threesome.
    If it is not physically close to the other two wires you have a loop antenna.
    The wires define the loop and the larger the loop's area the more effective it is at extracting energy from nearby lightning strokes. Google Biot-Savart.

    Same applies to the black and white wires - be aware that if they are not run together and a loop exists, that is a setup for your kind of troubles.

    just guessing, but it's always good to rule out the simple stuff.

    Hmmmmm what about those wires that go out to the photocells looking acrossbottom of door for tiny feet?
    Don't build a loop antenna around the door, run both wires together even though it might take some extra.

    old jim
     
    Last edited: Sep 11, 2011
  20. Sep 12, 2011 #19
    A direct lightning strike far down the street to AC wires is a direct lightning strike to every appliance in the house. Why are only some or no appliances damaged? A surge enters on one wire, does damage and stops? Of course not. That violates what everyone was taught in primary school science.

    First and electric current must have an incoming and a completely different outgoing path. The electricity exists simultaneously everywhere in that path. Long later, something in that path is damaged - ie the garage door controller.

    Again, the surge is incoming to everything. But only some things also have the outgoing path to earth. Those are the damaged appliances. This important concept taught in elementary school science is forgotten to create myths.

    Static electricity can be so massive as to make the hairs on your arms or head stand on end. And that still must not cause any appliance damage. Protection already inside each household appliance is so robust as to make trivial static irrelevant.

    Lightning rods only earth static when myths are promoted. Either lightning uses something conductive to connect to earth - ie wood. Or lightning is given a more conductive and therefore not destructive path to earth - ie the wire and earth ground wire that connects to a lightning rod. BTW, lightning rods do not do protection. Lightning rods only connect to what does protection; what absorbs hundreds of thousands of joules. That is earth ground.

    Earth ground explains why your garage door controller is damaged. For example, how many AC wires enter that garage? Two? Three? Four? If any wire does not connect direct to earth before entering the garage, then the controller has zero protection. A best path to earth is incoming on a 'hot' wire, through the controller, then out to earth via the wooden garage. Why does lightning strike wooden church steeples? Wood is an electrical conductor.

    Remember how damage happens. First, an incoming and another outgoing electric current path exists. Much later, electronics fail. That controller must be in a path from cloud to earth. Or it is not damaged. That explains what you must do to have no more damage.

    You have at least one wire entering the garage without a short (ie 'less than 10 foot') connection to single point earth ground. So that garage has no effective protectors. A protector adjacent to the controller (and too far from earth ground) might even make damage easier. But again, protection begins when you first define the incoming and outgoing current path from cloud to earth. A surge seeking earth (destructively) exists even when lightning strikes far down the street.
     
  21. Sep 12, 2011 #20
    So westom since I know nothing about electricity as I explained in my initial post, and therefore mostly what I read was blah blah, blah blah blah, blah, are lighting rods a good idea or not?

    No offense intended.
     
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