[RE-wrenches] 690.47D (revisited)
Kelly Keilwitz, Whidbey Sun & Wind
kelly at whidbeysunwind.com
Fri Jun 5 16:31:17 PDT 2009
Mark,
Yes, it's confusing. Which is why I wanted to know what the Wrenches are
actually DOING in their installations to meet 690.47D.
On 6/5/09 1:19 PM, "Mark Frye" <markf at berkeleysolar.com> wrote:
> Thanks Kelly,
>
> I haven't gotten the handbook, but I think I am getting the picture.
>
> How nice of the handbook to let us know that the new GE and GEC that "shall
> be installed" according to 690.47D is nothing more than an "optional
> supplementary ground electrode". And furher, if you do choose to take the
> option of installing it, in order to have the best lightning protection, you
> don't have to bond it to the exisiting GE system. How easy to now disregard
> 250.106 which says that 'The lightning protection system ground terminals
> shall be bonded to the building or structure grounding electrode system".
>
> Considering the inherant problems of 690.47D, I can certainly understand any
> AJH trying to avoid this issue of the creation of a whole new class of GE's
> who's use falls completely outside the basic definitions of 250 III 250.50,
> "All grounding electrodes.....shall be bonded together to form the grounding
> electrode system."
Remember, any other sections of the NEC are superceded by 690, if there are
conflicts (690.3)
Best,
-Kelly
Kelly Keilwitz, P.E.
Whidbey Sun & Wind, LLC
Renewable Energy Systems
NABCEP Certified PV Installer
987 Wanamaker Rd,
Coupeville, WA 98239
PH & FAX 360-678-7131
sunwind at whidbeysunwind.com
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