Can't bond ham shack ground to service entry ground

Discussion in 'General Technical Questions and Answers' started by AE0AQ, Mar 6, 2018.

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  1. K8MHZ

    K8MHZ Ham Member QRZ Page

    That's news to me. What if an operator doesn't meet code minimum? Do they get kicked out of the ARRL?

    I think you meant the above, which I agree with 100%.

    Although that is possible, I have never heard of that happening. Many NEC violations cause fires that the insurance companies pay for every day. In fact, I'll bet that most electrical fires are a result of an NEC violation. If the insurance companies only had to pay on NEC compliant claims, they would have almost nothing to pay out.

    Another point of issue is that the NEC is only applicable where adopted by law. It is not a law on it's own accord. Although most jurisdictions adopt the NEC in full or in part, there are some that do not, mostly rural areas with low population density.

    Too many people (not you, Dereck) think that the NEC is:

    The law for the entire country.

    A design specification.

    An instruction manual for untrained persons.

    It is none of the above.
     
    KA9JLM likes this.
  2. KF5LJW

    KF5LJW Ham Member QRZ Page

    Poor choice of words. Responsible.

    That is why I used CAN deny a claim.

    True and it comes down to money. In a rural area, your neighbors do not care if you burn your house and/or equipment up. Rural areas do not have the budgets to have a code enforcement agency, permits, or inspections. Not enough construction going on to pay for that department via permits and inspection fees. In cities things are different. Code enforcement agencies generate cash flow, and if your next door neighbor house is on fire 50 feet from your home, I bet you will care and be concerned. If your neighbors house fire damages your house, the Insurance companies are going to look for fault.

    This is why contractors and engineers are bonded and insured. The Insurance companies will go after the responsible 3rd party for reimbursement.

    I agree. It is a minimum set of safety requirements. What I will say if followed and complied with wil make your installation safe and should operate effectively. May not be the best practice, but it works and the least expensive. One good example is Bonding and Grounding as you pointed out in 820.100. There are two acceptable methods. A insulated 14 AWG ran along the outside wall within 20 feet is acceptable. Otherwise sink a rod, and run a 6 AWG below grade is a better practice.

    In a commercial application the code is complied with, but no commercial operator would do what a ham does. No multi-point ground or entrances. All services enter at roughly the same point to make a Single Point Ground so no outside fault can enter the building. AC Service, Telco, CATV, SATV, and Coax Hatch Plate are all within a few feet of each other bonded to a single point. It is called a Ground Window. For a fault to flow it has to have an Entry and Exit point.

    Easiest way to think about a Single Point ground is what I taught Mike years ago about Telcom Ground that clicks. Bond everything below grade together. Bond everything above grade together. Connect the two together at one point. If done correctly and to code, it is almost impossible to have lightning damage. I have investigated a lot of lightning damage for Telco's, data centers, commercial broadcast, and cellular tower sites. At every one I have found the Single Point Ground violated by someone installing something incorrectly. Most notable as we have discussed is missing isolation pads or bushings on equipment racks. Lightning allowed to come in on a signal cable, and exit where the equipment rack made contact with the floor without insulators and/or bushings. Concrete is an excellent conductor.
     
  3. KV6O

    KV6O Ham Member QRZ Page

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  4. N0TZU

    N0TZU Platinum Subscriber Platinum Subscriber QRZ Page

    Well gee, most of us aren't able to design and build a custom house, landscaping, and utilities around a ham radio antenna to achieve a true single point ground. Often the best that can be achieved is connecting the antenna ground rod to the service ground rod, and that run might be tens of feet. It's multipoint, but connected per code or better so voltage differences between the rods are minimized

    BTW, I don't know of any rural area where people don't care if a neighbor's house burns down, for a number of reasons including starting a grass fire or forest fire.

    Here in CO if a county doesn't have electrical inspections, then the state codes apply and the state will handle the permit and inspection. There's no such thing here as an area without codes or enforcement.
     
    Last edited: Mar 12, 2018
  5. W1GHD

    W1GHD XML Subscriber QRZ Page

    There is a consensus amongst knowledgeable people. There are excellent resources available, including the ARRL book on grounding and bonding, that spell things out pretty clearly.
     
  6. W6KCS

    W6KCS Ham Member QRZ Page

    It looks like there might be ways around this. For example, I use Belden's version of RG-214 that they call "8268", according to Belden it's a CMX spec cable, and 820.154(b) says CMX can be used in place of CATVX in dwellings.

    Dereck, I can't find a definition of "Limited Energy" as it applies to coaxial cable and as used by Mike in some of his documents on this topic, do you know what that means?
     
  7. K2EDM

    K2EDM Ham Member QRZ Page

    gnd for lightening...fine..BUT there is no such thing as an RF gnd!!
     
  8. KP4SX

    KP4SX Premium Subscriber QRZ Page

    Pretty nice work! But I have to nitpick :)
    I see the catwalk bonded to the panel but I don't see where the panel is bonded to ground. Nor do I see where the big conduit is bonded other than at the U-bolts to the catwalk.
     
  9. W6KCS

    W6KCS Ham Member QRZ Page

    I don't think we ground our feedthrough plates either. I usually do see a jumper from the outside bus through the plate to an inside bus for polyphasers. Maybe they aren't needed here for some reason. The big pipe supporting the cable bridge has a cadwelded jumper bolted to the bridge.
     
    Last edited: Mar 13, 2018
  10. KF5LJW

    KF5LJW Ham Member QRZ Page

    Wait for it.

    Spoke personally with Mike H, three other moderators and another peer about 810 and 820. FWIW all currently sit on NEC Code Making Panels and carry big sticks.

    Short story is what I said earlier, If a TX is involved, only 810 applies. Keep in mind Article 810 is for:
    UHF/VHF TV antennas, SATV, AM/FM/XM receiving, and CB/Amateur Radio TX equipment

    820 is written specifically for:
    CATV, CCTV, and Distributed Antennas Systems for Receive.

    OK Steve to answer your question about 810.3 coax installations. It only applies after a defined Demarcation point covered in 820.48 aka 50-foot rule. You can use unlisted ENTRANCE coax up to 50-feet to the 1st Termination Point. Beyond 50 feet or the first termination point, it must be listed.

    When it comes to coax, most ham operators do not use cheap Chi-Com counterfeit cables. In fact that is one area than ham radio operators will spend some extra cash. Most all quality coax I have seen is listed. Just do not pay up for Plenum rated coax unless necessary. Even Riser rated cable is expensive.
     
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