Grounding Do's Don'ts & Why Part 3

Discussion in 'Antennas, Feedlines, Towers & Rotors' started by KF5LJW, Mar 19, 2012.

ad: L-HROutlet
ad: l-rl
ad: L-MFJ
ad: DLSpec-1
ad: Left-2
ad: Subscribe
ad: MessiPaoloni-1
ad: Left-3
  1. KF5LJW

    KF5LJW Ham Member QRZ Page

    You are welcome

    No problem with that and a good idea. Sometimes required, other times not. Example if it were say 2/0 AWG up against the foundation and secured to the wall, no protection would be required. Weed whacker or lawn mower not a threat. However no harm or foul doing so if desired for cosmetics or piece of mind. You can get into trouble using say EMT or some other magnetic raceway or something magnetic encircling the conductor. It can be done but requires bonding of the conductor to pipe where it enters and exits to cancel out magnetic CHOKING EFFECT thus making the raceway part of the conductor. In fact NEC allows the certain raceways to be used as a Grounding/Bonding conductor. Very common practice found in many residential applications. Example if you look at your meter can, you may see a ground wire to the meter can and dead ends there. The Nipple or short piece of conduit penetrating that wall to your Breaker Panel is the Ground Bond between Neutral and Ground inside your Main nBreaker Panel Enclosure. Serves as both your Green Wire Equipment Ground and White Wire Neutral connection point. It will be those bars on either side inside Breaker Panel where you see both Green and White wires terminated for your branch circuits.

    You did good job and can sleep well knowing it is safe, operational, and compliant. It is Win-Win situation
     
    Last edited: Mar 18, 2019
  2. KG5WKO

    KG5WKO Ham Member QRZ Page

    I had to fall back to old location. I did ground radios surge on antennas and masts to ground and tied all together thru wire run around to utility panel. Best can do so antenna stays down in storms and hope I did it right. I have multiple ground rods in the run to avoid long runs as soil here is awful. Goal is not so much lightening as surges and static emps and transient spikes. Better ground seems right place to go then me and my rig.
    Still hear little green wire on plug solves all and one rod outside shack plenty. Do not bet on it.
     
  3. KG5WKO

    KG5WKO Ham Member QRZ Page

    What I did not clearly understand is lightening not my primary damage concern but here in NM hot dry windy and wires is build up of electrostatic energy. I took additional step to leave antennas grounded when off air. Got to see a discharge off end of coax due to this and I am duly impressed!
     
  4. M7DGY

    M7DGY Ham Member QRZ Page

    The knowledge I see being given so freely gives me a feeling of comfort for it is rarely seen these days and I would just like to say thank you for your post.
     
  5. W1OBJ

    W1OBJ Ham Member QRZ Page

     
  6. W9JEF

    W9JEF Ham Member QRZ Page

    From Part 1;
    https://forums.qrz.com/index.php?threads/grounding-dos-donts-why-part-1.335582/#post-2478347

    The image below shows the high voltage power line that runs along our road. The top wire, of course, is the hot side. Below it, is the neutral conductor, whose ground wire can be seen headed down the pole. Both conductor wires connect to the primary of the transformer we get our 240 VAC service from. So why do you say that “Utilities use the earth as a conductor” and “This causes normal load currents to flow in the earth” (instead of through the same-size neutral conductor)?

    [​IMG]
     
    Last edited: May 19, 2019
  7. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    How does one know it has absorbed a "direct hit" vs a partial discharge? I know my engineering education was in the dark ages, but I was taught that lightning protection systems were designed to absorb partial discharges prior to a large potential build up resulting in a "direct hit". Thus a lightning protection system "prevented" direct hits. At least that's what the Lightning Protection Institute used to infer in it's Black Magic courses.
    I've always considered Lightning Protection and Corrosion Protection to be Black Art. Whenever they failed they would blame the contractor for faulty installation even though both required certification. Either the science is not there or the certification process is poor.
     
  8. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    Utilities have been gravitating away from using earth as the return conductor for some time now. I'm willing that in under normal conditions very few utilities are using the earth as ground conductor. Short circuit conditions are of course a horse of a different color.
     
  9. WD0BCT

    WD0BCT Premium Subscriber QRZ Page

    Partial discharges are probably what you are referring to as direct hits. I think we have a difference in terminology here. I was taught (many years ago) that partial discharges prevented large potential build ups that could have much more severe results. At least that was the take by the LPI in those days.
     
  10. W9JEF

    W9JEF Ham Member QRZ Page



    From ARRL publication Energy Choices for the Radio Amateur by Bob Bruninga @WB4APR:

    [​IMG]
    According to page 10.8 of Bob's well-documented book:

    Although SWER distribution from the grid is not permitted in the National Electrical Code in the United States, the NEC does not apply to systems independent of the grid...

    In this example, the need was to deliver 100 W to my station more than a half mile away...”
     
    Last edited: May 22, 2019

Share This Page