From the '99 NEC (The current here in CA) 820-40 (b) Electrode. The grounding conductor shall be connected as follows. 1. To the nearest accessible location on the following: a. The building or structure grounding electrode system as covered in Section 250-50 b. The grounded interior metal water piping system as covered in Section 250-104(a) c. The power service accessible means external to enclosures as covered in Section 250-92(b) d. The metallic power service raceway e. The service equipment enclosure f. The grounding electrode conductor or the grounding electrode conductor metal enclosure, or g. To the grounding conductor or to the grounding electrode of a building or structure disconnecting means that is grounded to an electrode as covered in Section 250-32; or....
Sounds good so far, but 250-70 doesn't like that clamp. 3. For indoor telecommunications purposes only, a listed sheet metal strap-type ground clamp having a rigid metal base that seats on the electrode and having a strap of such material and dimensions that it is not likely to stretch during or after installation.
The Cu connection to the Al hub also is, I believe, a bust of 110-14, dissimilar metals
Code Compliant? I think not
[This message has been edited by electure (edited 04-09-2005).]
Re: Cable Company Grounding Methods#106436 04/09/0508:15 AM04/09/0508:15 AM
The 1/2" PVC in the first picture is protecting the GEC, which is connected to a ground rod. The cable guy did not run his ground wire to the nearest accessible location. I will be fixing this for my neighbor.
Re: Cable Company Grounding Methods#106437 04/09/0509:40 AM04/09/0509:40 AM
In a situation like this I once ran a small tail of #6 BC out of the bottom of the meter enclosure because I thought I had to make something available. The Poco inspector wanted it removed and accused me of drilling a hole for it too.
Re: Cable Company Grounding Methods#106439 04/09/0510:08 AM04/09/0510:08 AM
What made it worse was this was on a service upgrade and the Poco guy told the customer (I wasn't there) this was against code and I shouldn't have drilled a hole in the enclosure either, so you can imagine I got a call about it.
I explained to the customer the reason for the tail but told them I would come and remove it. (I asked if it seemed like the guy was drinking - I guess he's never seen the little KOs in the bottom of the enclosures).
Does anyone leave a tail like this? I thought it (or something) was required per 250.94 in situations like the one pictured.
Re: Cable Company Grounding Methods#106441 04/09/0503:18 PM04/09/0503:18 PM
Bill what really makes the use of this clamp foolish, is the #6 GEC was exposed 12" below the cable splitter where it attached to a ground rod. The cable guy had to run more #10 to go to the meter hub and install his clamp.
The tail you ask about. I have never seen one at the meter, but have seen tails at the panel board for the cable & alarm guys to use.
Re: Cable Company Grounding Methods#106442 04/11/0511:11 AM04/11/0511:11 AM
Ah! The "Cable Guys!!" I check grounding of the cable installer whenever I get the chance. It's doubly important with powered cable (<=150 v to grd) (From all those new meter pedestals on each street corner). Sometimes I get the comment from the cable installers that their work is not my business; they don't need a permit. After I give the recalcitrant ones a WRITTEN correction notice (with a copy to the job super) I explain that they still need to comply with Code req. even without a permit, I WILL comment on unsafe installs (80.23, 110.3 #8), and that, if not remedied, they could be disconnected and/or their system powered down(80.13). In their defense, most installers, when shown the importance of proper grounding, end up revising their work to passable levels.