Retrofit-Grounding Fifties-Era House?

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wrote:

That's simple.
Drill a hole all the way thru the core of the earth. Eventually, the drill will exit somewhere in China. Run a copper wire all the way thru this hole, and connect the far end of the wire to the ground rod of whoever has the closest house to your hole, in China. Then connect the near end to your breaker box ground bar.
That's all there is to it!
Plus, there's MORE.....
If your house ever gets hit by lightning, some idiot in China might get electrocuted. That's the price they pay for hating Americans.
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On Nov 16, 2:38 am, snipped-for-privacy@everywhere.com wrote:

Have you pulled the panel cover off and looked inside? The ground wired would be inside, tied together with the neutral. This was standard practice in the 50's. In the 50's having the system grounded was already standard practice. Back then, likely they would have tied it to the water pipe. But it's also possible there is a ground wire going somewhere.
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Per snipped-for-privacy@optonline.net:

Bingo for both.
They used solid copper instead the woven flexy stuff I was looking for... so it took awhile to recognize it.
In the context of the "Ground Fault" warnings from various UPS', though, I still think I need to have the ground electrically verified... I'm guessing there are tools for that and it's just a matter of finding the right person with the right tool.
--
Pete Cresswell

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wrote:

Possible that the ups is looking for a device ground at the outlet and does not have continuity back to the panel. It has no way to measure the complex ground/neutral panel connection. A voltmeter can be used to verify the ground integrity at the outlet. A 25 watt test bulb will indicate if the ground has a high impedance even though shown to exist by the voltmeter. Your house ground seems to be of the older rod plus pipe standard that was prevalent when built.
--
Mr.E

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The UPS would have no way of knowing if there is an actual earth ground of not. It could have a way of knowing if the outlet ground is connected to the neutral, but that's it.
There are two issues. One is if the panel has an earth ground, which you have now verified. The other is if the grounds from outlets are in fact connected back to the panel ground. If you're having problems with UPS faults about ground, I would suspect that the outlet does not have a ground path back to the panel.
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On 11/15/2012 6:02 PM, (PeteCresswell) wrote:

I assume this is the US, and there is an electrical code that is substantially the same as the National Electrical Code.
There are several major elements to the building "ground" system.
One is a bond between the neutral and service panel enclosure. The enclosure is the basic system "ground". The bond may be a visible strap. It can be a screw that just looks like a mounting screw for the neutral bar. This bonding is critical for tripping breakers when there is a short from, for instance, the hot wire in a drill to the metal drill case that is connected to the ground pin at a grounded receptacle.
Another element is one or more earthing electrodes. They are not for tripping breakers. They keep the building "ground" at approximately earth potential, and keep the hot and neutral wires at a reasonable potential with respect to earth.
The third element is grounding conductors that go with the branch circuit and connect to the ground terminal on receptacles. The grounding conductor can be a bare or green wire, or it can be the metal of the wiring system.
I would understand "building wiring fault" to mean that there is no branch circuit grounding conductor or there is no neutral-ground bond at the panel. The UPS has no way of telling if the building "ground" is earthed.

In the 50s the water pipe would have been entirely adequate as an earthing electrode. A metal water service pipe and metal municipal water system is still the best earthing electrode you will find at a house. Relatively recently a "supplemental" electrode has been required because the metal water service pipe can be replace by plastic in the future. The the N-G bonded service bar should have been connected to your water pipe (#6 wire is usually used for 100A services), and a bonding wire should have been connected across the water meter. The code now wants the wire from the panel to connect within 5 feet of where the water pipe enters the house. This will be your best earthing electrode.

This is the next best earthing electrode, but is only practical to add before the foundation is poured.

Ground rods can be driven at an angle or even installed flat. Ground rods are about the worst electrode.
Ask the electrical inspector what they would recommend.
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Great discussion and useful information. It wasn't a retrofit, but I do have thick layers of sandstone about 18 in. below grade (no basement!) and so made sure that the water and gas piping in the house, now about 10 years old, is bonded to the copper water supply pipe going to the street. The gas supply pipe is plastic. The water pipe is buried in a trench about 3 feet deep chipped out of the rock and back filled with sand and top soil.
The main panel is connected to a ground electrode which the contractor made by drilling down into the stone and putting in a copper rod. I've checked for a voltage difference a few times between the panel and the incoming copper water pipe and it measured zero on the most sensitive setting of the multi-meter. Probably that's because the top soil is usually moist to wet since rain water doesn't sink into the sandstone, but slowly moves horizontally keeping the region around the top soil and stone conductive.
The incoming water pipe and ground electrode are about 15 feet apart with no direct bond. Should there be one?
Tomsic
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On 11/17/2012 8:19 AM, .-. wrote:

Some gas utilities don't want their gas pipes bonded to the electrical. With a plastic supply it shouldn't matter. The way the NEC handles it is that metal gas pipe is connected to the building ground at appliances, like gas stoves and furnaces.

Zero voltage means there is little, if any, current to earth (shouldn't be much anyway).
Not obvious if it is from the description, but the water pipe should also be used as an earthing electrode. Water pipe and ground rod should both connect to the service panel neutral-ground bar. They can connect at the bar, or (if I remember right) the ground rod wire can connect to the water pipe wire at a convenient point. There should be a bond wire across the water meter.
My guess is that the resistance to earth is quite high. In a surge "event" the building "ground" will lift higher above 'absolute' earth potential than usual. Having short ground wires from entry protectors (phone, cable, dish, ...) to a common connection point on the earthing system is more important than most houses. And the distance from the service N-G bond to the common connection point should also be short. You want all wiring to rise together.
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YES!!!! and the water meter should have a jumper, since meters can be poor conductors and mayy be removed at some time
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If I wanted to learn more about all this, what would I read. Preferably something that didn't simply say what the code demanded, but rather something that *explained* enough so that you'd be able to look at various grounding systems and be able to tell the pros and cons of each.
Any ideas?
David
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On Tue, 15 Jan 2013 06:33:21 +0000 (UTC), snipped-for-privacy@panix.com (David Combs) wrote:

Various? The code is the code.

Use GFCIs.
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On 1/15/2013 12:33 AM, David Combs wrote:

The grounding chapter of the NEC is likely the most confusing of the commonly used chapters. I have accumulated information over many years.
The best source may be "Soares book on gounding and bonding" published by the International Association of Electrical Inspectors. At almost 400 pages it is overkill for most people.
http://ecmweb.com/bonding-amp-grounding/grounding-vs-bonding-part-1-12 is a 12 part series from EC&M magazine (which is very good magazine, or was when I was reading it). [HeyBub used one page as a source, which had an error, likely oversimplification that was probably fixed on a later page. I have not read the whole series.]
I read a book on "grounding" from the library and took strong exception to several pieces.
You can ask questions here, but sometimes it is hard to know what to ask.
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On 1/15/2013 12:33 AM, David Combs wrote:

It's unlikely w/o much detailed study and more background than you'll get you'll be able to discern "pros and cons" other than what is outlined for some given situation by any particular author.
An overall practical non-journeyman's guide is
<(Amazon.com product link shortened)>
It's based on given revision of NEC but is written as narrative-style rather than simply the Code sections and has introductory chapters that are good for getting concepts for the neophyte/non-engineer/non-techschool trained...you'll not be ready for licensing exam but you'll have a good start and have info at hand for most household/farmstead/_light_ manufacturing that likely to run across outside actual commercial/industrial applications.
--
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Dont forget to install a ground jumper between the 2 sides of the water meter, meters dont make good conductors and might be removed at some time.
And bond all grounds together. otherwise ground loops can occur.
Having grounds at different potentials can cause a hazard if anyone gets across 2 different potential ones. Nasty shock can occur:(
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Excellent "white paper" on grounding and the neutral-wire here:
http://www.apcmedia.com/salestools/SADE-5TNQYQ/SADE-5TNQYQ_R1_EN.pdf
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Hey, anyone go look at that stuff?
They have a variety of interesting "white papers" there.
If you have looked at any of it, how about commenting back here, suggesting that others do or do not go there themselves.
David
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