[TowerTalk] Grounding Rod Lenght

Alan C. Zack k7acz at cox.net
Mon Feb 16 19:53:54 EST 2004


Jim,
Good info here.  Question please.  If a city Building Department is
requiring your antenna tower project to be to code, can you request to
study the code from one of their books?
Reason I ask is I'm in the process of getting a building permit for a
small tower.  U.S. Towers provided me with drawings and wind calcs for
70 MPH.  Not good enough.  The US Towers drawings are to USB-97 specs,
they want IBC-2000 specs.  The wind specs are to 70 MPH, they want 90
MPH.  Sales at U.S. Towers has refereed it to their outside contracted
PE.  They don't have an in-house PE.  They farm stuff like this out to
a contracted PE then charges the customer for the info.  Still better
than trying to find someone from scratch to do it for you.  Any
possible suggestions?  (I am an EE and IE but not a PE)
Thanks.......

Jim Lux wrote:
> 
> You won't find the NEC online; it's copyrighted, and the publisher, NFPA,
> which goes to some expense to create the code, would prefer to be paid for
> their labors.  If you're in a business subject to "the code", it's probably
> worthwhile to spend the $50 and get a copy, especially if questions like
> this come up very often, or if you operate in a litigious environment.
> 
> Transcript during deposition:
> Q: What precautions did you take to mitigate damage from electrical
> transients for our client's equipment?
> A: We installed grounding rods and other grounding equipment.
> Q: Was this installation in accordance with any recognized system or
> process?
> A: Yes, it was entirely to code.
> Q: What do you mean by "to code"?
> A: In accordance with the National Electrical Code, the NEC.
> Q: Do you have ready access at your workplace to the current edition of the
> NEC?
> A: No.
> Q: Do you have any version of the code at your workplace?
> A: I think we have one from 1985, and not much has changed since then, for
> what we're doing.
> Q: How do you know that the installation is in accordance with the code
> A: By training and experience
> Q: Does that training use the printed NEC?
> A: No.
> Q: What sort of training materials do you use?
> A: The foreman just tells us what to do.
> Q: Does the foreman have a copy of the NEC?
> A: I don't know
> Q: Thank you, no further questions
> "
> 
> The above is paraphrased from an actual deposition I was involved in... you
> don't want to be there, no way, uh-huh... It's exceedingly uncomfortable for
> the poor guy being questioned and to watch it from the sidelines, as I
> was.The guy probably actually knew the content of the code better than
> anybody else involved, from years of practical application and study.
> But... he didn't have the "artifacts" to prove it.
> 
>  Buy the darn book and be done with the arguments.  It's one thing when it's
> a ham doing his own work or helping out his buddies. It's entirely another
> when you're doing it as part of a business.  Likewise, the IEEE "Green Book"
> or "Emerald Book" might be worth getting. Both cover aspects of grounding,
> the former for big stuff, the latter for smaller, more sensitive stuff.
> 
> Practically speaking, the grounding requirements vary, depending on the
> usage.  What's good for telecom may not be good for radio (since they are
> covered by different parts of the NEC).
> 
> There's some real useful material on grounding for low voltage systems at
> the Mike Holt website (http://www.mikeholt.com/ ?)
> including a good (free) handbook on the current requirements applying to
> grounding radios and other Class II, low voltage installations.
> 
> Jim Lux
> 
> ----- Original Message -----
> From: "James" <jameswarren at swbell.net>
> To: <towertalk at contesting.com>
> Sent: Sunday, February 15, 2004 9:37 AM
> Subject: [TowerTalk] Grounding Rod Lenght
> 
> > I'm disagreeing with a manager about the length of grounding rods.
> >
> > He's a former small town independent telephone outside plant manager
> > and said they used 4' rods, so if it was good enough for the telephone
> > company, its good enough for his satellite and two-way radio
> installations.
> >
> > When I did southwestern Bell contract, they required 8' rods on
> everything,
> > which is more in line with current National Electric Code.
> >
> > I tried a Google search for NEC Sections 210 and 850 (?) that pertain to
> > ground, but only found references and no direct quotable links.
> >
> > Any help on this?
> >

-- 
__________________________________________________________________________                       
                                     Alan Zack
                     Amateur Radio Station K7ACZ
                         Las Vegas, Nevada, USA
          Quality Engineer, The Boeing Company, Retired
  Aviation Chief Warrant Officer, U.S. Coast Guard, Retired
        U.S. Coast Guard, Always Ready, Always There
Every hour, Every day, Around the Clock and Around the World
                               SEMPER PARATUS


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