[TowerTalk] Cadweld vs clamps

[Jim Lux]

On 10/26/14, 9:09 AM, N3AE wrote:
> The question of tying grounds together seems to come up often. I started a thread a few weeks back with a question on tower grounding which was hijacked into a spirited discussion on ground-to-neutral connections in outbuilding load panels.
>
> Guess I'll know the "official" position shortly. Just called to schedule a final inspection for my tower project only to learn I had to pull an electrical permit too. Previously I was told I did not need electrical. Local officials seem to make it up as it goes along. At my QTH however, only a Master Electrician licensed in the county can pull an electrical permit, so it seems I must now hire someone to ground my tower, deal with bonding, coax suppressors, etc to requirements in Article 810 of the 2011 NEC. The challenge will be finding a local licensed electrician who is familiar with these requirements as most work around here is residential and small business/light industrial.
>
> To jump into the current discussion, I believe I have to follow Figure 15 from the link below. We can argue the physics like distance and voltage differential due to propagation time, but at the end of the day it's just the inspector's opinion that matters.
>
> I'll provide a summary later of how it goes.
>
> http://www.reeve.com/Documents/Articles%20Papers/AntennaSystemGroundingRequirements_Reeve.pdf
>
> Shawn - N3AE
>


Reeve's writeup is very good, and his comments on the  handbook chapter 
(of which I am the author/editor for the most part) are well taken.

As he points out, the NEC is sort of a hodgepodge that has evolved over 
the years, and modern versions are MUCH more consistent and use better 
terminology than older versions (2014 is the latest edition). Be aware 
that your local jurisdiction may not use the latest version (mine 
doesn't).  I think for the most part that compliance with the latest 
version won't cause problems with an inspector looking for compliance 
with an older version (and in any case, it's the inspector's word that 
is final)




With respect to guidance to amateur radio licensees, either in the 
handbook or online in forums such as this, there is a fine line to be 
walked between "strictly according to code" and "what people are 
actually likely to do".

A good example is the code requirement for "listed antenna discharge 
units", of which there are none suitable for amateur HF antenna use (at 
least that I've found.)

Another is that I doubt that most wire antennas meet the code 
requirements of hard drawn copper or copper clad steel of the gauges 
required in the code.  We can hand wave a bit and say that wire antennas 
made with AWG20 wire are temporary in nature, and may fall under one of 
the exceptions for such things; nobody would expect a AWG 20 magnet wire 
antenna to stay up for very long.



On local codes vs NEC..
Here's mine:
That certain Code designated as the “California Electrical Code,” 2013 
Edition, based upon the 2011 National Electrical Code, including Annex C 
and D, published by the National Fire Protection Association, at least 
one (1) copy of which is on file in the Office of the Building Official 
for public record and inspection, is hereby adopted by reference and 
made a part of this chapter as though set forth in this chapter in full, 
subject, however, to the amendments, additions and deletions set forth 
in this chapter, and said Code and provisions shall be known as the 
Electrical Wiring Code for the City.

and then goes on later...
...served by adding to and amending the California Electrical Code, and, 
therefore, said California Electrical Code, 2013 Edition, is hereby 
amended to read as follows...


Among which is this
Article 90.4. Enforcement.
    (A)   Used Electrical Equipment.
    Unless otherwise approved by the Building Official, all electrical 
equipment installed in the City of Thousand Oaks shall be new and shall 
be listed by a recognized testing laboratory. Used equipment may be 
installed when sufficient documentation has been received and approved 
by the Building Official. The documentation shall consist of tests by a 
recognized testing laboratory sufficient enough to warrant and certify 
the equipment as safe for the intended use.

-> a strict reading of this means that you can't install that used 
electrically actuated telescoping tower, or for that matter, perhaps 
even a used ham rig.

-> This is where having a non-confrontational agreeable attitude with 
the local authorities helps. Especially if you have someone looking to 
stop your project who is looking for this kind of stuff.  If the local 
inspector (aka Building Official) signs off, it's good.