Help with ground electrode conductor from panel to ?


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Old 12-01-13, 07:44 PM
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Help with ground electrode conductor from panel to ?

Hey all,

I recently had my plumbing redone and all my galvanized pipe removed from a newly purchase house. Turns out they had grounded my 150 amp electrical panel to a part of the galvanized pipe not within 5 feet of it entering the building, and there doesn't appear to be any additional ground. The ground electrode conduct coming out of the panel is AWG 6 sheathed (black sheath, right side of panel in pic) and terminates about 5 feet away on a piece of galvanized pipe the plumbers left sitting in the basement. I want to run either 1) a new continuous conductor from my panel to the water pipe stub entering the ground, which is about 30 feet from the panel, and then bond the ground to two grounding rods right outside from the water line entrance.

Is there an easy way to splice the GEC (I know code is pretty specific, either a permanent crimp or a copper bus bar, just never done either), or should I run a new continuous 6 (or 4) to the water line?

Then, is it ok to bond the ground right outside the water line to two grounding rods (now 40-50 feet from panel)?

I am trying to avoid wiring inside the panel if I can, but I want to do this correctly. Also, anyone have a good method for driving ground rods?

Thanks in advance for the help!
 
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Old 12-01-13, 07:57 PM
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Forgot the pics

Sorry, I forgot the pictures, here they are:

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Size:  45.1 KBName:  Ground in Panel.jpg
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Size:  31.5 KBName:  Grounding Water Pipe.jpg
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Old 12-01-13, 07:58 PM
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Driving ground rods .... my favorite.

I usually use a 4' ladder and a big sledgehammer. You can drive them with a ground rod driver bit in a Hilti drill if you know an electrician. If you're in rock..... say a little prayer. Be sure to keep them a foot or so off the foundation in order to miss any footings.

As far as the ground wiring.... it should be continuous but on a job I just did the inspector recommended a non removable crimp as the ground wire was run thru a finished house and could not be replaced. The crimps can be diecast or copper and take a big crimp tool to crimp them. A bug or setscrew type connector is not allowed as a ground splice.

For a 150 amp service I would use #4 copper.

You can connect the grounds to the main water supply point inside.
You can also place them near the panel and add the second wire to the neutral/ground bar if room allows.

On edit:
Based on your pictures.... I would replace the existing ground wire with a continuous new one.
 
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Old 12-01-13, 08:26 PM
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PJMax,

Thanks a ton, so you would do a #4 from the panel where the current ground is located (pic 3 I think) using a continuous line to the old discontinued water pipe (pic 4)?

The wire would be run through the joists above my basement, so would it be alright to use a sheathed #4? I think the only ones I ran into were braided, or should it be solid in your opinion?

I'm not sure if I have a spot for a second ground wire that can handle a #4, do you happen to see one? If not, I suppose I'll just jump the ground rods off the water pipe that will get the continuous GEC to the breaker.

Thanks for the help, first time GEC installation here, so want to make sure I do it correctly.
 
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Old 12-01-13, 09:43 PM
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I would run the ground to the new water service so that the service is bonded to ground and so is the house plumbing.

I don't see an additional place in your panel for a #4 but sometimes there are a few larger openings in the neutral bar where a #4 could fit.
 
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Old 12-02-13, 07:21 AM
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I recently had my plumbing redone and all my galvanized pipe removed from a newly purchase house.
Is your new piping copper or plastic? Your new GEC is based upon the size of the service entrance conductors. You said you have a 150 amp service and code allows either #1 copper or 2/0 aluminum for a residential 150 amp service, you have aluminum. Based on that, I would say your GEC to the water service entry point can be either #6 copper or #4 aluminum. I would place the ground rod/rods directly outside from the service panel and use #6 copper to it. Outside from the service panel and above the ground rod, you need to add an intersystem bond to satisfy 2008 NEC requirements.

Arlington | Intersystem Grounding Bridges

Your telephone, cable TV, satellite TV, etc all should be grounded by attaching to the intersytem bonding bridge which clamps onto your GEC before it clamps to your ground rod.
 

Last edited by CasualJoe; 12-02-13 at 08:57 AM. Reason: correct typo
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Old 12-02-13, 07:58 AM
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The old ground wire to the galvanized pipe does not count because it was clamped on more than 5 feet from where the pipe exited the house. So you need to start from scratch.

You need one grounding electrode conductor non-stop from the panel neutral bus bar to either the new water pipe (if metal) or to ground rods. You may splice on additional #6 copper wire for GEC to the other (ground rods or pipe).

If the new water pipe is plastic as it exits the house, then you would still need a ground wire of the same size going to (anywhere on) metal plumbing in the basement. This wire is now called a bonding jumper rather than a GEC.

Since you need ground rods, there is no point in re-using the galvanized pipe. I wouldn't use the galvanized pipe as you have it since there is no way of knowing if or when it corrodes underground outside to the point where it no longer qualifies as a grounding electrode (ten feet of metal contacting earth). On the other hand, if it were still carrying water, bonding it would both be required and would satisfy requirements, and it would not be disqualified until long after the point where it leaked badly out there.

When you drive new ground rods near the panel, the other ground rods further away need no treatment except if you use them for grounding things like cable TV then you need to add them to your grounding electrode system by running additional GEC (splicing allowed).
 

Last edited by AllanJ; 12-02-13 at 08:22 AM.
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Old 12-02-13, 10:00 AM
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Man, you guys are really helping me out. I appreciate it. It looks like there are some more factors in play, so I'll provide some more detail and so we can get a finalized plan.

The new plumbing is Pex, so it's plastic, and the new service from the street is plastic as well. The only metal I have remaining is copper runs in a few select places (mainly going to shower heads, lavatories, or hose bibs, and are all connected to the main Pex lines. Do I need to bond all of these small runs?

The old water line, as can be seen in picture 4 above, is discontinued. Is it still worth trying to use this as a conductor, or just best to leave it alone? AllanJ makes a good point about it no longer being in use, and possibly rotted away. The only reason I liked the idea is that there is a good exit to the outside nearby the old pipe, but it is a good bit away from the panel. Directly outside the panel is a carport, so if I run anything out that way I'll have to secure it to the wall of the house, across the roof of the carport (wooden ceiling) and then down into the backyard for the rods. This is certainly doable, but won't be as hidden/out of the way as if I went out of the side of the house near the old water entrance. However, it will be closer (possibly) to go out near the panel. Is there a real benefit to going closer to the panel, or would either work?

So it looks like either #4 or #6 would work for this application, I may just err on the side of caution with the #4 since I plan on possibly upgrading to a 200amp panel sometime. Is it OK to run stranded plastic sheathed wire for the ground? (especially if it will be visible going outside and up the wall near the panel) I don't want bare copper running all over, for aesthetic reasons. Is there any downside to sheathed stranded?

I don't have any coax or phone lines right now. Just an internet connection, which the ATT guy grounded recently. Should I mess with a bridge if this is the case?

Thanks guys, you are really helping me out a ton!
 
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Old 12-02-13, 05:20 PM
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Since your new piping and water service is non-metallic you don't need a ground to the water service, but the sections of copper piping need to be bonded to the panel ground. I would just put the ground rod at the nearest point possible since you have the carport. I prefer 7 strand bare copper ground wire to a rod, but insulated is allowed. A #6 copper ground wire, GEC, is all that is necessary even for a future 200 amp service. The intersystem grounding bridge is a code requirement, that is where the AT&T guy should have terminated his ground wire, it's required to be bonded to the panel ground. I'd go ahead and install it so any future installations can also be properly grounded.
 
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Old 12-02-13, 05:28 PM
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The way the code is written it states metallic piping "systems" need to be bonded. IMO your sections of metallic lines are not a system and would not require bonding. I also do not think they would meet the definition of "likely to become energized". The best bet would be a call to your building officials.
 
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Old 12-02-13, 07:00 PM
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The way the code is written it states metallic piping "systems" need to be bonded. IMO your sections of metallic lines are not a system and would not require bonding. I also do not think they would meet the definition of "likely to become energized". The best bet would be a call to your building officials.
That's a good point. With the increased useage of pex systems there are some grounding and bonding questions out there that haven't been fully addressed in the NEC yet, IMO.
 
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Old 12-02-13, 07:08 PM
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I wish the NEC would make a stand on bonding CSST. It is not covered very well under the NEC, yet the gas code requires the bonding.
 
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Old 12-03-13, 05:32 AM
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Gas pipes do not qualify as grounding electrodes. But the gas piping needs to be bonded to the electrical ground and you have a choice of methods. If you use a #6 ground wire from a gas pipe to a ground rod, it's a bonding jumper, not a grounding electrode conductor. Should your bonding jumper first reach a GEC already installed, it may be clamped on there rather than go the rest of the way to the panel or a ground rod.

One reason for bonding a ground rod used for your telephone connection to the rest of your grouning electrode system is because oncein awhile the telephone equipment itself is not crrectly grounded and a voltge difference between the phone ground and the house ground fries something.
 
 

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