Acceptable Lightning Ground?
Jimmie D wrote:
"Thomas Horne" wrote in message k.net... And my point is that your opinion does not jibe with the National Electric Code. -- Tom Horne Please Tom, tell me in what way that the grounding system should be sufficent on its own and not having to rely on the plumbing to provide grounding for an electrical system in violation of the NEC. In violation of the NEC?? Underground metal water pipe was a required electrode in the oldest NEC I have, 1968, and I think it has been required since shortly after Columbus ‘discovered America’. Also please tell me how you intend to prevent the scenario I discribed where the ground system was completely disconnected from the home when the well's metal plumbing was replaced with plastic. For that very reason the NEC requires a “supplemental” electrode. As the “NEC Handbook” makes clear, the supplemental electrode is not required because metal water pipe is a bad electrode, only because it may be replaced in the future by plastic. The supplemental electrode was commonly one or two ground rods. Rods are a little better than nothing - a rod-to-earth resistance of 25 ohms is considered acceptable, or install 2 and resistance doesn’t matter. With a supplemental rod, if an underground metal water pipe is replaced with plastic a good grounding electrode system becomes a poor system. The 2005 NEC generally requires adding a “concrete encased electrode” in new construction . This is actually a decent electrode. The Code is the min and max that an inspector can apply to an inspection This means that the inspector cant find fault with using plumbing for grounding if this is what the code says, it doesnt mean that the inspector can find fault if it is built better than code requirements, so again I say the code is written to a minimum spec. Your own definition of min max confirms this. Traditionally the NEC has the lowest minimum standard and the state and local codes usually have a higher standard., there may be some exceptions to this. I will will stipulate that using plumbing for ground may be "to code" in some places but it still is not a good way to ground your house and definately should not be used for a lightning ground. Using underground metal water pipes for grounding is “to code” anywhere the NEC is adopted and not modified. That is a major piece of the US. The requirement to use metal water pipe as an electrode dates back a long time and is substantially unchanged. The authors of the NEC see metal underground water pipe as an effective grounding electrode. As Thomas said, “your opinion does not jibe with the National Electric Code”. You also don’t say what your improvement over water pipe is. If installing lightning rods a different NFPA standard is used. If installing a lightning rod in the form of a tower or high antenna it would also be wise to look at other standards. ----- Regarding corrosion, water pipe corrosion has been investigated by the International Association of Electrical Inspectors and the National Institute of Standards and Technology, and corrosion problems were found to be minimal. -- bud-- |
Acceptable Lightning Ground?
It was much simpler when old boilers were easily obtained and could be buried in the back yard! Just a fond memory. Irv VE6BP |
Acceptable Lightning Ground?
"Bud--" wrote in message ... Jimmie D wrote: "Thomas Horne" wrote in message k.net... And my point is that your opinion does not jibe with the National Electric Code. -- Tom Horne Please Tom, tell me in what way that the grounding system should be sufficent on its own and not having to rely on the plumbing to provide grounding for an electrical system in violation of the NEC. In violation of the NEC?? Underground metal water pipe was a required electrode in the oldest NEC I have, 1968, and I think it has been required since shortly after Columbus ‘discovered America’. Also please tell me how you intend to prevent the scenario I discribed where the ground system was completely disconnected from the home when the well's metal plumbing was replaced with plastic. My point exactly, and who is going to replace the pipe, definately not an electrician that will make sure the ground system is maintained. For that very reason the NEC requires a “supplemental” electrode. As the “NEC Handbook” makes clear, the supplemental electrode is not required because metal water pipe is a bad electrode, only because it may be replaced in the future by plastic. The supplemental electrode was commonly one or two ground rods. Rods are a little better than nothing - a rod-to-earth resistance of 25 ohms is considered acceptable, or install 2 and resistance doesn’t matter. With a supplemental rod, if an underground metal water pipe is replaced with plastic a good grounding electrode system becomes a poor system. The 2005 NEC generally requires adding a “concrete encased electrode” in new construction . This is actually a decent electrode. The Code is the min and max that an inspector can apply to an inspection This means that the inspector cant find fault with using plumbing for grounding if this is what the code says, it doesnt mean that the inspector can find fault if it is built better than code requirements, so again I say the code is written to a minimum spec. Your own definition of min max confirms this. Traditionally the NEC has the lowest minimum standard and the state and local codes usually have a higher standard., there may be some exceptions to this. I will will stipulate that using plumbing for ground may be "to code" in some places but it still is not a good way to ground your house and definately should not be used for a lightning ground. Using underground metal water pipes for grounding is “to code” anywhere the NEC is adopted and not modified. That is a major piece of the US. The requirement to use metal water pipe as an electrode dates back a long time and is substantially unchanged. The authors of the NEC see metal underground water pipe as an effective grounding electrode. As Thomas said, “your opinion does not jibe with the National Electric Code”. You also don’t say what your improvement over water pipe is. If installing lightning rods a different NFPA standard is used. If installing a lightning rod in the form of a tower or high antenna it would also be wise to look at other standards. ----- Regarding corrosion, water pipe corrosion has been investigated by the International Association of Electrical Inspectors and the National Institute of Standards and Technology, and corrosion problems were found to be minimal. -- bud-- |
Acceptable Lightning Ground?
Jimmie D wrote:
"Bud--" wrote in message ... Jimmie D wrote: "Thomas Horne" wrote in message link.net... And my point is that your opinion does not jibe with the National Electric Code. -- Tom Horne Please Tom, tell me in what way that the grounding system should be sufficent on its own and not having to rely on the plumbing to provide grounding for an electrical system in violation of the NEC. In violation of the NEC?? Underground metal water pipe was a required electrode in the oldest NEC I have, 1968, and I think it has been required since shortly after Columbus ‘discovered America’. Also please tell me how you intend to prevent the scenario I discribed where the ground system was completely disconnected from the home when the well's metal plumbing was replaced with plastic. My point exactly, and who is going to replace the pipe, definately not an electrician that will make sure the ground system is maintained. No one needs to replace the pipe. The system has a "supplemental" electrode - that is why the "supplemental" electrode is REQUIRED. The effectiveness of the grounding electrode system is reduced to what you wanted without the water pipe. With ground rods for the "supplemental" electrode that effectiveness is rather low. With a "concrete encased" electrode now generally required, the effectiveness is pretty good. -- bud-- For that very reason the NEC requires a “supplemental” electrode. As the “NEC Handbook” makes clear, the supplemental electrode is not required because metal water pipe is a bad electrode, only because it may be replaced in the future by plastic. The supplemental electrode was commonly one or two ground rods. Rods are a little better than nothing - a rod-to-earth resistance of 25 ohms is considered acceptable, or install 2 and resistance doesn’t matter. With a supplemental rod, if an underground metal water pipe is replaced with plastic a good grounding electrode system becomes a poor system. The 2005 NEC generally requires adding a “concrete encased electrode” in new construction . This is actually a decent electrode. |
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