Discussion in 'General Technical Questions and Answers' started by AE0AQ, Mar 6, 2018.
So, what are the 'applicable requirements' of 820? The only references to 820 I see in 810 is 810.3 that says coax cables connecting antennas to equipment shall comply with Article 820 and 810.4 that says a CATV antenna must comply with 820.
We are not CATV, so 810.4 is N/A
So which parts of 820 applies to ham radio, and how did we get to those parts?
Do the listing requirements of 820.113 and 820.179 apply to coax connecting antennas to equipment apply to ham radio?
Does the grounding conductor for the coax shield have to be insulated and listed as per 820.100 (1)?
Does the grounding conductor have to be LESS than 20 feet in length as per 820.100 (4).
I was going to post the above or similar on Mike Holt's Forum, but since Dereck showed up here, I will run it by him.
For those that have never seen a recent edition of the NEC, it's 8"x11", over 1000 pages long. It's very confusing and you have to 'jump all over the book' to get an answer. It's a book one needs to take classes on to use. Entire books are written about how to use and understand the NEC. Web site forums exist to discuss what the NEC means. There is even a practice of reading and understanding the NEC called 'Codeology'. There is even a book on codeology, Applied Codeology Navigating the NEC. The way the NEC is written, two people can read the same article and get two different meanings.
You are welcome. To be honest I rarely see any Ham Radio Operators fully comply with article 810.
Some how, somewhere, some bone head without a clue what they were doing came up with this idea Radio equipment should not share a common ground with the utility or anything else for that matter. That myth keeps being handed down to this day. Not only is it extremely dangerous, it can seriously degrade operations particularly reception (RX).
810 is not hard to follow. I see a lot of excuses and my favorite excuse is: "Hams cannot afford to follow rules and comply with codes". All I can say to that is if you cannot afford to comply with minimum safety requirements, then you cannot afford to play with radios inside your home. Keep the toys in your vehicle so you do not put anyone else life in danger.
Hams PLEASE READ THIS. It will tell you what you need to do to meet MINIMUM REQUIREMENTS in plain English.
Winner winner chicken dinner. The coax has to be listed.
820.100(1) is confusing. The answer is YES is it is a Bonding Jumper ran on the side of the structure above grade.
820.100(2) Yes if ran on the structure above grade.
Now for the NO answer. If it exceeds 20 feet, sink a ROD and run a bare 6 AWG Bonding Jumper below grade and call it a Radial or thing a bob.
Watch the video where Mike and I answer your questions.
I don't see where listed coax is required for amateur radio. Please cite the section of 810, which points to 820, which requires listed coax for an amateur radio installation.
As per 179, there are only four listed coax types allowed, all are CATV. CATVP, CATVR, CATV and CATVX. Do those even exist in 50 ohm? RG-8, for instance, is not permitted under the listing requirement of 820.179. What's up with that??
I am having trouble with the listing requirement here. I don't think I have ever seen a single conductor with a listing (outside of appliance wiring), let alone one for grounding.
That makes sense, as per the exception.
One more question. There are three different grounding conductor size and material requirements in 810/820. Which one do we use?
810.58 (B) No smaller than 10 AWG copper,bronze or copper clad steel.
810.58 (C) Not less than 14 AWG or its equivalent.
820.100 (A) No smaller than 14 AWG, copper or other corrosion conductive material, Listed, insulated
Also, only 820.100 (A) has a length limitation requirement.
VI. Listing Requirements
Common sense would think that the listing requirement would not apply to amateur radio, but if one applies 820 (which I personally don't think applies to Part III), then the listing requirements for coax apply to ALL coax that is not excluded under the exceptions.
I see Mike sidestepped the 'listed' part of the grounding conductor when questioned about it.
I'm just an amateur NEC reader (pun intended), but I don't see where there is any requirement for listed coaxial cables for an amateur station.
Article 820 requires them for various situations but that article is for CATV plants and such. I can't find any connection to an amateur station.
Even if it did apply somehow, 800.48 allows unlisted outside cables to go up to 50 ft inside a building in normal spaces if there is primary protector (in our case, an ADU or shield ground) at the point of entry. And, that same exception is also in 820.48 though it says a grounding block rather than primary protector.
The most salient article, 810 Part III (Amateur and CB Transmitting and Receiving Antenna Systems), says that other applicable sections are in 810, but doesn't mention 820.
Please correct me if I'm misinterpreting something.