1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Do you think your dish is immune to lighting? Think again…

Discussion in 'DIRECTV Installation/MDU Discussion' started by sptrout, Oct 8, 2007.

Thread Status:
Not open for further replies.
  1. eandras

    eandras Godfather

    427
    1
    Feb 15, 2007

    They are protected by halo grounds with ground wire that are cadmium welded to ground rods located around the tower (creating a circle). In addition the antenna lines are grounded every 10 feet using a ground kit that is connected to the copper shield in the cable. The lines that connect to the equipment all have polyphasers (lightning arrstors) on the return lines that do not allow power (lightning) to pass through. This system will help alleviate trouble but in the end the lightning damage would occur.


    PS: Polyphasers will not work on the satellie lines. I tried and it would not pass the voltage through the line.
     
  2. joe diamond

    joe diamond Hall Of Fame

    3,071
    0
    Feb 28, 2007
    Here is more,

    From another source...lightning rods and sailboat masts provide a "cone of protection" that goes out 45 degrees from the tip of the lightning rod / mast.
    So, can one ground a system to a lightning rod and expect ok results?

    Joe
     
  3. lowspeed

    lowspeed AllStar

    65
    0
    Oct 8, 2007
    Does this thoery make any sense?

    By not grounding the dish, the lighting will "Prefer" not going through the dish, because its not the easiest route to the ground.
     
  4. JeffBowser

    JeffBowser blah blah blah

    2,549
    18
    Dec 21, 2006
    I have never heard that. In fact, I would venture to say that that statement is guilty of violating laws of physics..... :D

    jb

     
  5. paulman182

    paulman182 Hall Of Fame

    4,839
    3
    Aug 4, 2006
    Do you know this for a fact or is this supposition? The plan specifically mentions power surges as being covered, and most damaging power surges are caused by lightning somewhere into the power grid.
     
  6. aim2pls

    aim2pls Icon

    560
    0
    Jun 18, 2007

    hundreds of thousands of dishes say yes
     
  7. lowspeed

    lowspeed AllStar

    65
    0
    Oct 8, 2007
    The question is, is it more likely for it to hit the dish grounded or not.
     
  8. aim2pls

    aim2pls Icon

    560
    0
    Jun 18, 2007

    grounding a dish raises the ground potential to the dish (vs earth) .. if the dish is the highest point that is grounded ... wood is a very poor conductor ... then yes you are making it into a lightning rod
     
  9. JeffBowser

    JeffBowser blah blah blah

    2,549
    18
    Dec 21, 2006
    On the other hand, if the dish is not grounded, it may have higher "electrical visibility", and we know that lightning is nothing more than "nature's" attempt to equalize charges......

     
  10. lowspeed

    lowspeed AllStar

    65
    0
    Oct 8, 2007
    This is a great idea for mythbusters.
     
  11. Phlakey

    Phlakey New Member

    2
    0
    Apr 6, 2007
    By not grounding the dish, you insure that any stray currents that my come in contact with it will go directly to your reciever.

    Other ungrounded items on a roof that frequently recieve lightning strikes;

    Metal fireplace chimneys and gas water heater vent pipes.
     
  12. lowspeed

    lowspeed AllStar

    65
    0
    Oct 8, 2007

    I think with the grounding or not your stuff is fried if i lighting hits it. no ?
     
  13. PR Buick

    PR Buick AllStar

    61
    0
    Oct 12, 2006
    Okay, I just realized that when my installer replaced my old dish last year with the 5LNB for my HR-20 setup, he didn't run a ground wire from the new one. The new dish is installed a foot or so closer to the box & multiswitch--he just cut the old cable and ran two new ones from the 5LNB, sans grounding wire.

    I can see that the old cables are still up there, and their attached ground wire is still connected to the grounding block (that then connects to a post on our electrical meter.)

    However, the coax for my internet connection also connects to this same grounding block and then goes into the same end of a diplexer that also meets up with one of the cables coming out of my multiswitch. (They go to a room with an SD receiver--I've got a splitter in the room) Since there is this roundabout grounding connection with the dish, through the multiswitch, is that enough? (Again, I don't know if it matters that the cable from the dish is going into the same side of the diplexer that has the grounded coax cable) OR, do I need to go ahead and see if I can connect my existing, stand-alone grounding wire that's just so much roof decoration? (Hope all that makes sense...)

    Also--dumb question-- but if I go ahead connect the grounding cable to the dish, where does it attach? Is there a particular screw just for this? (I tried finding an installation manual on the D* website, but couldn't and it's not easy for me to get up there and take a look)

    Thanks!
     
  14. Glidedon

    Glidedon New Member

    3
    0
    Oct 7, 2007
    I connect my dish to a 1 iron.

    Not even God can hit a 1 iron :)
     
  15. joe diamond

    joe diamond Hall Of Fame

    3,071
    0
    Feb 28, 2007
    ==========
    PR

    On the mast base there may be a 3/16 hole for the self tapping green ground screw that is shipped with the dish. If not found just loosen one of the mast alignment bolts and feed the ground wire between the nut & the base. Tighten without breaking the bolt.
    Using a dish attachment bolt is considered bad form.

    Joe
     
  16. PR Buick

    PR Buick AllStar

    61
    0
    Oct 12, 2006
    Thanks!
     
  17. Greg Alsobrook

    Greg Alsobrook Lifetime Achiever

    10,453
    0
    Apr 1, 2007
    i would rather lightning hit my dish.... would probably save a lot of damage to my house...
     
  18. K4SMX

    K4SMX Hall Of Fame

    3,433
    0
    May 19, 2007
    This is actually quite well-established both in theory and in practice to the extent that probability tables are published at one and two standard deviations of probability for both 45 and 60 degree "cones of protection."

    There have been a lot of things said in this thread with which I take exception, and I don't really want to debate each and every issue. Suffice it to say that for the very reason that lightning is so dangerous to life and property, there is a very large amount of published technical information regarding means of protection.

    You will find that ungrounded outdoor antenna systems of any type are considered inherently dangerous, that there are well-established techniques for minimizing but not eliminating this danger, and that the more thoroughly you ground an antenna system (including its feed lines) the more protection you obtain for everything inside the "cone of protection."

    Whenever I have made recommendations about this subject in these forums, it has always been with a view toward basic, standard procedures. You can always do more, and it's not rocket science: large conductors running by as straight a path possible to as large a dissipation grounding system as you can reasonably provide and NO available diversion paths once a strike occurs.

    While it is true that lightning "only" kills about four or five hundred people per year in this country, many more are permanently injured, and it does a tremendous amount of property damage, including many homes burned to the ground.
     
  19. Greg Alsobrook

    Greg Alsobrook Lifetime Achiever

    10,453
    0
    Apr 1, 2007
    but i bet you would also have to have your coax run through the surge strip as well for you to quality... i'm not sure... but read the fine print... i don't like running my coax through surge strips/backups because i see a noticeable depreciation in quality...
     
  20. Clato

    Clato Banned User

    265
    0
    Aug 30, 2007
    ==============================
    What was it said about ,"GOD himself couldn't sink the Titanic there isn't anything that is man/machine made that cannot be destroyed, by an act of GOD or Nature...
     
Thread Status:
Not open for further replies.

Share This Page