Correct box and electrode connectors for GEC?

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kenjsil

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I posted something like this back in 2001, and never really got it cleared up. I'd like to see if there are any new products anyone can recommend:

Around here (Los Angeles), the usual residential service is 3-wire #1 with the GEC run in #6 CU solid armored or #4 CU solid bare. The electodes for most older and some new construction are the water service pipe and a 5/8" x 8' driven rod.

If you use the armored #6 GEC:
The armor has to be bonded at both ends. There are water pipe ground clamps with lugs for the armor as well as the conductor like the Burndy C11JA or C6D, and we sometimes use these for ground rod connections (with the clamp reversed to make a tight connection) or we just mash the armor into an acorn clamp. At the LC, we use a 3/8" MC connector or an Rx clamp on the armor (with a grounding bushing if it's in a multiple KO).

For the #4 w/o armor:
We use an Rx clamp at the box or just run the conductor through a small hole provided for that purpose (I think). There's no problem finding listed clamps for the groumd rod or water pipe electrode in this case.

I haven't had trouble getting AHJ approval with any of the above, but it still bothers me that I don't really know the correct listed connectors to use for the GEC on the most common residential service. So, what connectors would YOU use for:

1. #4 Solid CU GEC to LC
2. #6 Solid CU Armored GEC to LC
3. #6 Solid CU Armored GEC to Ground Rod

BTW, the whole armored GEC application bothers me because the 8' rod is supposed to be completely buried, but then the connector has to be approved/listed for burial (which the Burndy C6D is) but the armor itself isn't as far as I know. In fact, the armor rapidly degrades when it's in contact with soil even in dry Los Angeles. So, we generally don't drive the rod all the way, which is possibly the lesser of two evils.

A lot simpler to run the GEC in rigid or IMC, at least I'd know what fittings to use - but of course it would be too expensive...
 
Re: Correct box and electrode connectors for GEC?

I personally would avoid using any type of metallic means as a raceway for the GEC. The use of RNC is more than sufficent and can be installed below the ground allowing the ground rod to be installed the full 8' feet. :)
 
Re: Correct box and electrode connectors for GEC?

You can sink the rod all the way as long as your clamp is approved for direct burial OR you exothermic weld the connection "Cad-Weld it".

You know, you can always buy a 10' ground rod and not have to worry about the underground connection.

I am in Los Angeles too.....
I do this:
10' ground rod driven 9+ feet deep on an angle
1/2 EMT from H20 to ground rod
1/2 EMT from ground rod to can

Three brass ground clamps with 1/2 "threaded hubs" are used. Two for the ground rod and one for the H20 pipe. Bond bushing grounding/bonding lock nut as applicable in the service can.

Conductor is "looped through" both clamps on the ground rod. No splices here.

DWP & B/S = happy, happy, happy
 
Re: Correct box and electrode connectors for GEC?

Thanks very much, I like both suggestions. Much more workmanlike than the armored.

MSD -

Do you think DWP & B/S would be happy with RNC (as bphgravity suggests). I've never asked or tried it.

- Kenneth
 
Re: Correct box and electrode connectors for GEC?

RNC is acceptable to supply physical protection for the GEC. It can be installed above or below grade.

However, if you are planning to make a connection below grade BE SURE you have a connection (to the ground rod) listed for direct burial.

Personaly, I would stay away from the RNC simply because of "Pride in Workmanship". Nothing screams CHEAP like plastic. Remember that the NEC is a minimum standard. Just because code allows something dosen't mean it is a necessairly a quality install. Spend a few extra bucks for the metal parts and do a good job.
 
Re: Correct box and electrode connectors for GEC?

Originally posted by msd:
Personaly, I would stay away from the RNC simply because of "Pride in Workmanship". Nothing screams CHEAP like plastic. Remember that the NEC is a minimum standard. Just because code allows something dosen't mean it is a necessairly a quality install. Spend a few extra bucks for the metal parts and do a good job.
Click to expand...
I strongly disagree with this statement. I do not believe RNC is an inferior wiring method to any metallic means. This issue is more than a matter of workmanship, it is a matter of effectiveness.

Metallic raceways containing single conductors will act as an inductor and could severely "choke" the current flow from lighnting or other fault events.

Section 250.92(A)(3) provides a requirement to help limit this potential, however it can easily be avoided by providing a non-metallic raceway instead. :)
 
Re: Correct box and electrode connectors for GEC?

Just personal opinion here but I do not like PVC run exposed, I do not find that it looks good over time, almost no one follows the support requirements.

However for the protection of GECs or work in corrosive environments it is IMO a better way to go.

I am amazed that the NEC considers schedule 80 PVC to provide protection from physical damage. :)
 
Re: Correct box and electrode connectors for GEC?

I thought it was achock only if you don't bond @ both ends of conduit.
Eric
 
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