I am extending the ground for the service panel with two 8' rods because the pipes were re-done in PVC. I plan to attach #4 wire to the end of the existing #6 wire with two copper split-bolt connectors and make the connection real tight. I have been reading that the copper ground wire should be one continuous wire. However I pefer not to mess with high voltage and take apart the service panel to make it one continuous ground wire. Are the split bolt connectors sufficient or is there some "physics" reason it must be one wire? Or is it to prevent someone from accidentally un-screwing the bolt?
One continuous conductor, unless spliced with an irreversible connections such as an exothermic weld (solder is not good enough). Do you have access to a good torch? I would use a split bolt connector and then after tightening it braze shut it with 40% silver solder. Solid #6 wire should be enough; no need to use #4 unless the wire is subject to being damaged by a lawn mower or something.
Exothermic welding is a chemical weld, not brazing. They refer to a product like CadWeld which is a copper laden thermite type powder. You put a mold around the joint, pour it full of this powder and light it. When the fire goes out you have a solid mass of copper around the joint. If he can get to the first rod with the copper he has he can jumper to the second rod.
Thank you Bob, I'll braze the split bolt connector. I have a torch that I used years ago to fix a copper water pipe. I don't remember how to solder with it but I think I can find some crash course on the net. Still a bit curious how this affects the physical properties of the electricity running through the wire.
I understand that; a thermite weld. I think brazing (with silver) a copper or bronze split bolt connector so it cannot be loosened is a reasonable approximation.
No this will only be at an electrical supply house. The mold is the expensive part. It is a lot of work to go through to avoid simply replacing the wire.
It's due to the destructive power of a lightning strike. The idea is to make it as easy as possible for the lightning to get to ground without damaging anything. There aren't supposed to be sharp bends in the wire to the ground rod either. The wire isn't supposed to be wrapped around anything. It's supposed to be as straight as possible. #6 is specified since a ground rod can handle only so much current anyhow. Going to a larger size wire won't help a whole bunch.
You need to redo it with a continuous wire, unless you are equipped to weld (not solder) the wires together. This is generally only done on big commercial work and is done with exothermic welding gear which you in all probability don't have.
Assuming this is a residential scenario, the service panel does not contain high voltage, it contains 240V. Even if it's commercial it isn't likely above 480V which is still not high voltage.
If you really don't feel safe working in the panel, install your ground rods and the wire all the way back to the panel leaving plenty of extra and then have an electrician stop by and make the connection in the panel.
Please don't do that. No offense, but you'll probably just make a mess of it. Even if you can make a decent braze, brazing is not accepted by NEC. Here is an acceptable ground clamp, readily available at Home Depot:
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Usually referred to an "acorn nut," the one in the link is for 1/2" ground rods. They are also available for 5/8" rods. It helps to slide the acorn nut(s) onto the the ground rod _before_ driving it, if using a sledge hammer, as the head tends to mushroom, making it a PITA to install the acorn nut after the fact.
Pete C and gfretwell had some good suggestions. If I were doing it, I would drive the first ground rod as close to the electric service as possible, preferably 18" away from the house so it is at or outside of the roof drip line. Drive the second rod one rod length away from the first rod and trench between the rods. The deeper the better. I use #4 bare copper since it is not required to be protected. As Tom Horne has stated in other threads in this NG, if you're going to do all that, it would be better and about as much work to establish a "ground ring" while you're at it. A minimum ground ring would require using #2 bare copper at least 20 feet long and buried at least 30 inches.
After driving the rods (preferably 5/8" copper), run the wire from the panel to the first rod, through the acorn nut without slice then on the the next rod. Then working your way back to the panel, connect the wire to the second rod, tighten the ground clamp at the first rod, then connect to the panel. De-energize the main panel breaker before removing the original grounding system wiring.
If you still insist on using a split bolt, which is not acceptable by NEC if the splice is before the first rod, at least use one that is listed for the purpose, which usually means using one made of brass, overlap the wires about one foot and use two split bolts.
Good advice! Just want to add, to help the 'grounding' effect, the code requires those rods 6 feet apart, but make them 8. Easy way to do this, drive the first one, then lay the second one on the ground, and then that's 8 feet.
The idea about the splice, it should be in such a way that over a long time, nothing can work it's way loose. The grounding system with the rods stablizes voltages and can help extend the life of many of your home's electronics. So it's a good idea to follow the NEC requirements, and do it once right.
Remember, not your electrician, so just my options. ;)
Good tips. I should note that the existing ground wire coming out of the service panel ends at a clamp on a copper pipe. This copper pipe was cut somewhere not too far under the ground for the PVC. I wasn't around when this re-piping project was done, but I am getting crazy voltages, 134V at a couple outlets, and 4V difference between this ground wire and the fence post, so I'm sure this is part of the problem. I was intending to leave the copper pipe clamp like it is and just "extend" the system so it can also benefit from this little pipe section. I will make sure it is done right, probably leave some extra wire near the service panel till I figure out how to make the connection.
It should, but that's up to the inspector (if there is one.) A split bolt connector is a compression joint. When you solder the threads (especially using hard solder), you've made it irreversible.
Just make sure it looks neat. Don't try to solder or braze the wires, the silver solder is just to make the split bolt connection permanent.
Nothing right or wrong in the ground system can causse you to have 134 volts at an outlet and you will never stop having voltages between differing grounds. The advice you have been given is good, you need a good ground and it needs to be done according to all applicable codes. Having 134 volts at an outlet can only be a result of excessive input from the power company or a high resistance in the neutral line. Having voltages between different grounds is perfectly normal and will always exist.
It turned out to be a power company problem. While driving in the ground rods I looked up and noticed that the neutral line connector was broken off at the power pole! So I called out the power company and Southern CA Edison showed up within an hour to fix it. Now the voltages are reading normal at the outlets.
If you can find an electrical inspector who will pass a hack job like that, I'd like to know his/her supervisor's name. Now that you bring it up, making major changes to an electric system ground _is_ something that should be inspected by a local electrical inspector, if there is one.
The NEC is very clear that the grounding electrode conductor must be continuous, without splice. The NEC also realizes that buildings get remodeled and that situations, such as the OP's, do occur. For those reasons the NEC, specifically (2002) Section 250.64(C), does permit splices to be made and _only_ made by an "exothermic welding process", i.e. CadWeld, or by "irreversible compression-type connectors LISTED for the purpose."
A silver-soldered split bolt is _not_ a listed irreversible compression type connector. Both a CadWeld and the tool required to crimp the irreversible connectors are beyond the capabilities of most residential electrical contractors, mostly due to cost, let alone a home owner. Cadweld does make a disposable One Shot, but that is for connection of wire to ground rods. AFAIK, CadWeld doesn't make a wire to wire One Shot. The OP could call around and find a commercial electrical contractor who may rent him a crimping tool for irreversible connectors, but that would probably be cost prohibitive too.
As long as it's neat a hack job is OK? I once saw a house wired with lamp cord. Sure was neatly installed, though. Just one of those things that one just doesn't believe until one sees it. I once found a
120 volt duplex receptacle wired with telephone wire, but it wasn't neat, the wire wasn't stapled.
All this, just because the OP doesn't feel comfortable getting inside the main panel, and now you've got him out in the dirt with a torch? I've been doing electrical work for 30 years and I've yet to see an electrician with a torch, with the exception of maybe using a propane torch to dry out a damp CadWeld mold before using it, or to fire off the starter powder because his ignitor took a dump.
If you have interior metal water pipes, IMO, you should leave that wire and clamp alone, other than to check to see that it is tight, or to replace the clamp if it is corroded. If your interior water pipes are metal and that wire is removed, in the event that the pipes accidentally become energized by a circuit or equipment, a serious shock hazard will exist. Also, if your interior pipes are metal, and the water meter is inside the house, it should be jumpered. The hot water line should also be jumpered to the cold water line at the water heater. Same for any water conditioning equipment, etc.
This is exactly why NEC requires that an underground metal water used to ground an electric system be supplemented with a ground rod....somebody comes along and replaces the underground water pipe with plastic. IIRC, this requirement came about around 1978 or so. If your house is newer than that, you may want to take a closer look and try to find a wire that may already go to a ground rod.
You could drive the ground rods and run the wire, leaving enough extra wire to reach both the panel and the old connection at the water pipe. That way when the electrical contractor comes to make the connection they will have a choice. Even though the NEC permits them to make a crimp connection to the wire at the water pipe, they may refuse to do it. I know I would. It's better practice and easier (for someone willing to go into the panel) just to take it to the panel.
Since you don't feel comfortable getting inside the panel, I think Pete C.'s suggestion was best.....do all the other work, then call a qualified electricial contractor to make the final connection to the panel.....while they are at it they can check what you did to be sure everything is OK.
Proper electric system grounding is critical, and unfortunately, improper grounding is usually not evident until a fault occurs, then it's too late.
If you do decide to make the connection to the panel, for safety, especially in this case, since you have no existing system ground, it's important that the final connection to the panel be made while the panel is de-energized.
It would probably be best to call your local electrical inspector to see if an inspection is required.
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