Frank:
Thanks - that's the reference I had in mind. What I correctly recalled
was the requirement for six electrodes (ground rods) for self-supporting towers
such as my own; I hosed up on the reference (ANSI/TIA-222) and on the number of
wires to those six electrodes.
73 de
Gene Smar AD3F
-------------- Original message ----------------------
From: <donovanf@starpower.net>
> Effective January 1, 1006; tower grounding standards in the United States are
> specified in ANSI/TIA-222-G-2005.
>
> Section 10.4 states:
>
> Connections between a structure and grounding electroes or connection between
> electrodes shall be compatible with the electrodes and be accomplished by
> leads
> no smaller in surface area than 2/0 solid.
>
> Gounding electrodes shall be as a minimum, be equivalent to 5/8 inch
> diameter,
> 10 feet long metal rods constructed of copper, copper clad steel, galvanized
> steel or stainless steel alloy. The minimum embedment depth of grounding
> electrodes shall be 10 feet. All electrodes must be connected to the
> structure,
> however, all electrodes need not be interconnected
>
> Section A.10.0 Protective Grounding states:
> It is intended that the owner or the owner's representative will verify that
> total resistance will not exceed 10 ohms based on actual on site soil
> conditions. Additional grounding electrodes may be required.
>
> For guyed masts the default grounding configuration shall be a minimum of
> three
> grounding electrodes installed symetrically around the base of the structure
> at
> a minimum 20 ft spacing and each symetrically connected to the base of the
> structure. A minimum of one grounding electrode shall be installed and
> connected at each (guy) anchor.
>
> For self supporting structures, the default grounding configuration shall be
> a
> minimum of six grounding electrodes installed symetrically around the base of
> the structure at a minimum of 20 feet spacing. A mimumum of one lead shall
> be
> connected to each leg for latticed structures and a minimum of thee leads
> shall
> be symetrically connected to the base of pole structures.
>
> 73!
> Frank
> W3LPL
>
>
> ---- Original message ----
> >Date: Thu, 4 Jan 2007 12:11:44 -0500
> >From: <ersmar@comcast.net>
> >Subject: Re: [TowerTalk] Antenna/Tower Grounding (Lightning Protection)
> >To: "Richard W. Solomon" <w1ksz@earthlink.net>, <towertalk@contesting.com>,
> "Jim Lux" <jimlux@earthlink.net>
> >
> >Jim:
> >
> >----- Original Message -----
> >From: "Jim Lux" <jimlux@earthlink.net>
> >To: <ersmar@comcast.net>; "Richard W. Solomon" <w1ksz@earthlink.net>;
> ><towertalk@contesting.com>
> >Sent: Thursday, January 04, 2007 10:10 AM
> >Subject: Re: [TowerTalk] Antenna/Tower Grounding (Lightning Protection)
> >
> >
> >
> >>>2. Your tower ought to have at least one ground wire, minimum of #8
> >>>gauge wire, to one ground rod within two feet of each tower leg. The
> >>>latest version of the National Electrical Code mandates two ground rods
> >>>and two wires at each leg.
> >>
> >>
> >> Really? Which code? The 2005 NEC is silent on towers, per se. Art 810.15
> >> says masts and metal structures shall be grounded in accordance with
> >> 810.21. 810.21 just has the stuff about the size of the wire, straight
> >> line runs, protection of the connections, and what can serve as a
> >> grounding electrode.
> >>
> >> Art 820 (CATV etc) has very similar provisions.
> >>
> >>
> >> Maybe you're thinking of some lightning protection code? Or a
> >> recommendation of a manufacturer?
> >>
> >>
> >> Jim, W6RMK
> >>
> >>
> >
> > I'm pretty sure I read about these new grounding requirements in the
> >latest (2008) proposed NEC here on TowerTalk within the past six months or
> >so. I can't just yet find that reference in the archives. I'll do more
> >searching and report back to the reflector. But I'm just as certain what I
> >read was not something from a manufacturer.
> >
> >73 de
> >Gene Smar AD3F
> >
> >
> >
> >
> >
> >_______________________________________________
> >
> >
> >
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>
>
>
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