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#1
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Conducting concrete
Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator!
Sorry, can't find the post it was mentioned in. -- A man goes home early and catches another man in bed with his wife. He drags the naked man out of the house and into his garden shed. There he secures man's penis in a vice and removes the handle, then starts to sharpen a knife. The naked man shouts, "You're not going to cut it off are you?" "No, you are," was the reply. "I'm going to set fire to the shed" |
#2
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Conducting concrete
On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote:
Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. |
#3
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Conducting concrete
On Wed, 4 Jan 2017 10:31:06 -0800 (PST), trader_4
wrote: On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. Ah yes, the old Ufer ground. That protected a lot of ordinance throughout the years. |
#4
Posted to uk.d-i-y,alt.home.repair
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Conducting concrete
On 1/4/2017 9:58 AM, James Wilkinson Sword wrote:
Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. |
#5
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Conducting concrete
On Wed, 04 Jan 2017 10:42:34 -0800
mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules plus he is the local dole whore loon. |
#6
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Conducting concrete
On Wed, 4 Jan 2017 10:31:06 -0800 (PST), trader_4
wrote: On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. Best I can tell, my foundation has an Ufer ground. Inside the exterior wall there is a ground rod going down into the concrete. Might be tied into the cable tension cables in the foundation. This is in the desert. |
#7
Posted to uk.d-i-y,alt.home.repair
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Conducting concrete
On 1/4/2017 10:48 AM, burfordTjustice wrote:
On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. plus he is the local dole whore loon. Count up YOUR posts and try to say that again with a straight face. |
#8
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Conducting concrete
On 04/01/2017 18:48, burfordTjustice wrote:
snip plus he is the local dole whore loon. And you aren't? |
#9
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Conducting concrete
On Wednesday, January 4, 2017 at 1:48:38 PM UTC-5, burfordTjustice wrote:
On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules plus he is the local dole whore loon. I see, you're so dumb you think the laws of physics, the conductivity of concrete is different in the UK than in the USA. |
#10
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Conducting concrete
On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote:
On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) -- The average lifespan of electronic devices is between zero and infinity, or 2 days after the warranty runs out, whichever comes first. |
#11
Posted to uk.d-i-y,alt.home.repair
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Conducting concrete
On Wed, 04 Jan 2017 18:42:34 -0000, mike wrote:
On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. Why did you want inspection? When you do work on your house, you don't tell anyone. -- Pub sign: Liquor in the front, poker in the rear. |
#12
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Conducting concrete
On Wed, 04 Jan 2017 18:31:06 -0000, trader_4 wrote:
On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. Only if the concrete stays wet. Which won't happen unless it rains a lot. -- I don't have OCD - I'm just defragmenting the universe. |
#13
Posted to uk.d-i-y,alt.home.repair
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Conducting concrete
On Wed, 04 Jan 2017 20:00:22 -0000
"James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) LOL Please post a picture of you taking the measurement. |
#14
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Conducting concrete
On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword"
wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp |
#15
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Conducting concrete
On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. |
#16
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Conducting concrete
On Wed, 04 Jan 2017 21:04:15 -0000, wrote:
On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword" wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp If your floor is damp all the way through, you have bigger problems. Concrete floors are for garages, houses should have wood floors suspended above the ground. What century is the USA living in? -- In 1839, the imperial Chinese commissioner Lin Zexu wrote a letter to Queen Victoria warning that, unless the British stopped supplying opium to China, he would cut off rhubarb supplies to Britain, killing everyone through mass constipation. |
#17
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Conducting concrete
On Wed, 04 Jan 2017 21:11:26 -0000, wrote:
On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. -- A military pilot called for a priority landing because his single-engine jet fighter was running "a bit peaked." Air Traffic Control told the fighter jock that he was number two, behind a B-52 that had one engine shut down. "Ah," the fighter pilot remarked, "The dreaded seven-engine approach." |
#18
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Conducting concrete
On Wed, 04 Jan 2017 20:02:30 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 18:31:06 -0000, trader_4 wrote: On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. Only if the concrete stays wet. Which won't happen unless it rains a lot. This was originally designed for ammo dumps in the desert so try again. Where you live, it is always wet isn't it? The effectiveness is in the contact area, not any single point. |
#19
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Conducting concrete
On Wed, 04 Jan 2017 21:11:44 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 21:04:15 -0000, wrote: On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword" wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp If your floor is damp all the way through, you have bigger problems. Concrete floors are for garages, houses should have wood floors suspended above the ground. What century is the USA living in? One where we have not solved the termite, hurricane and tornado problems? |
#20
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Conducting concrete
On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. Don't tell me you are one of those scotsmen who wear panties. |
#21
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Conducting concrete
On Wed, 04 Jan 2017 22:12:42 -0000, wrote:
On Wed, 04 Jan 2017 20:02:30 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 18:31:06 -0000, trader_4 wrote: On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. Only if the concrete stays wet. Which won't happen unless it rains a lot. This was originally designed for ammo dumps in the desert so try again. First time I've seen ammo dumps mentioned. We're talking about houses, concrete floors, and the dangers of being earthed. Where you live, it is always wet isn't it? Yes, but not inside the house. The effectiveness is in the contact area, not any single point. The top surface of the concrete in the house isn't wet. If it is, your carpet would go mouldy. -- A man has six items in his bathroom: toothbrush and toothpaste, shaving cream, razor, a bar of soap, and a towel. The average number of items in the typical woman's bathroom is 337. A man would not be able to identify more than 20 of these items. |
#22
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Conducting concrete
On Wed, 04 Jan 2017 22:14:30 -0000, wrote:
On Wed, 04 Jan 2017 21:11:44 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:04:15 -0000, wrote: On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword" wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp If your floor is damp all the way through, you have bigger problems. Concrete floors are for garages, houses should have wood floors suspended above the ground. What century is the USA living in? One where we have not solved the termite, Chemicals are your friend. hurricane and tornado problems? Those tend to affect walls and roofs. -- What's the difference between a naked white woman and a naked black woman? One's on the cover of Playboy and the other's on the cover of National Geographic. |
#23
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Conducting concrete
On Wed, 04 Jan 2017 22:16:19 -0000, wrote:
On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. What part of 20MOhms didn't you understand? Don't tell me you are one of those scotsmen who wear panties. I go commando. -- I just took a leaflet out of my mailbox, informing me that I can have sex at 75. I'm so happy, because I live at number 71. So it's not too far to walk home afterwards. And it's the same side of the street. I don't even have to cross the road! |
#24
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Conducting concrete
James Wilkinson Sword pretended :
On Wed, 04 Jan 2017 22:16:19 -0000, wrote: On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. What part of 20MOhms didn't you understand? https://engineering.purdue.edu/~conc...hapter%203.pdf |
#25
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Conducting concrete
On Wed, 04 Jan 2017 22:56:57 -0000, FromTheRafters wrote:
James Wilkinson Sword pretended : On Wed, 04 Jan 2017 22:16:19 -0000, wrote: On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. What part of 20MOhms didn't you understand? https://engineering.purdue.edu/~conc...hapter%203.pdf So as I said before, it's the water conducting. But your floor really really shouldn't be damp. -- A "Frisbeterian" believes that when you die, your soul goes up on the roof and you can't get it back down. |
#26
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Conducting concrete
On Wed, 04 Jan 2017 22:17:02 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 22:12:42 -0000, wrote: On Wed, 04 Jan 2017 20:02:30 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 18:31:06 -0000, trader_4 wrote: On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. Only if the concrete stays wet. Which won't happen unless it rains a lot. This was originally designed for ammo dumps in the desert so try again. First time I've seen ammo dumps mentioned. We're talking about houses, concrete floors, and the dangers of being earthed. The danger is not being earthed when you are talking about ammo and this was the most effective way to earth them. Where you live, it is always wet isn't it? Yes, but not inside the house. The effectiveness is in the contact area, not any single point. The top surface of the concrete in the house isn't wet. If it is, your carpet would go mouldy. It is wet enough to ionize the stuff in concrete. I didn't make this **** up on the spot, google Ufer. |
#27
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Conducting concrete
On Wed, 04 Jan 2017 22:22:05 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 22:14:30 -0000, wrote: On Wed, 04 Jan 2017 21:11:44 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:04:15 -0000, wrote: On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword" wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp If your floor is damp all the way through, you have bigger problems. Concrete floors are for garages, houses should have wood floors suspended above the ground. What century is the USA living in? One where we have not solved the termite, Chemicals are your friend. Fine when they work and don't migrate to the ground water. hurricane and tornado problems? Those tend to affect walls and roofs. If your floor is off the ground, it will just be part of the debris field when the wind gets up under it. |
#28
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Conducting concrete
On Thu, 05 Jan 2017 00:01:52 -0000, wrote:
On Wed, 04 Jan 2017 22:17:02 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 22:12:42 -0000, wrote: On Wed, 04 Jan 2017 20:02:30 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 18:31:06 -0000, trader_4 wrote: On Wednesday, January 4, 2017 at 12:58:25 PM UTC-5, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Wrong as usual. Concrete that's been cured and then dried out, kept away from moisture, may not be a good conductor. But building concrete, a foundation is such a good conductor, it's the preferred ground for the building electrical service. An electrode is placed inside it before the pour. Only if the concrete stays wet. Which won't happen unless it rains a lot. This was originally designed for ammo dumps in the desert so try again. First time I've seen ammo dumps mentioned. We're talking about houses, concrete floors, and the dangers of being earthed. The danger is not being earthed when you are talking about ammo and this was the most effective way to earth them. Perhaps, if the concrete is guaranteed to be wet, but then the ammo would get damp. But I wasn't talking about ammo. Where you live, it is always wet isn't it? Yes, but not inside the house. The effectiveness is in the contact area, not any single point. The top surface of the concrete in the house isn't wet. If it is, your carpet would go mouldy. It is wet enough to ionize the stuff in concrete. I didn't make this **** up on the spot, google Ufer. It simply isn't true, I tested it. -- Someday we'll look back on all this and plough into a parked car. |
#29
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Conducting concrete
On Wed, 04 Jan 2017 22:22:46 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 22:16:19 -0000, wrote: On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. What part of 20MOhms didn't you understand? Try it and get back to me. That is 20meg at one small point. If you can find 2 pieces of rebar with 20' in contact with the concrete, check that to ground or another rebar in the same slab. "Earth" is a pretty bad conductor in the first place so what you are really trying to create is an equipotential ground grid. Don't tell me you are one of those scotsmen who wear panties. I go commando. Cool, especially when the wind is blowing in off the North Sea in January. ;-) |
#30
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Conducting concrete
On Thu, 05 Jan 2017 00:05:58 -0000, wrote:
On Wed, 04 Jan 2017 22:22:05 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 22:14:30 -0000, wrote: On Wed, 04 Jan 2017 21:11:44 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:04:15 -0000, wrote: On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword" wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp If your floor is damp all the way through, you have bigger problems. Concrete floors are for garages, houses should have wood floors suspended above the ground. What century is the USA living in? One where we have not solved the termite, Chemicals are your friend. Fine when they work and don't migrate to the ground water. Not my problem. hurricane and tornado problems? Those tend to affect walls and roofs. If your floor is off the ground, it will just be part of the debris field when the wind gets up under it. If the walls are gone, why do you care about your floor? -- I can kind of understand why Muslims get so frustrated. I mean, how many more people are they going to have to murder before everyone understands that Islam is the religion of peace? |
#31
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Conducting concrete
On 1/4/17 2:00 PM, James Wilkinson Sword wrote:
It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) I guess one doesn't test earth grounding with a regular ohm meter. The instructor at one of my code refresher classes asked once if anyone had the correct type of tester. No one did out of at least 50 electricians. Earth grounding is primarily for damage from lightning. He also had a diagram showing how little current would flow through the earth if a well motor had a short to the frame. The resistance was so high that there was no way even a tiny fuse would blow if there was a short. This is from the meter maker Fluke: http://support.fluke.com/find-sales/Download/Asset/2633834_6115_ENG_A_W.PDF |
#32
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Conducting concrete
On Wed, 04 Jan 2017 23:31:13 -0000, "James Wilkinson Sword"
wrote: On Wed, 04 Jan 2017 22:56:57 -0000, FromTheRafters wrote: James Wilkinson Sword pretended : On Wed, 04 Jan 2017 22:16:19 -0000, wrote: On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. What part of 20MOhms didn't you understand? https://engineering.purdue.edu/~conc...hapter%203.pdf So as I said before, it's the water conducting. But your floor really really shouldn't be damp. The Ufer ground is not in the floor, it is in the foundation but your concrete floor still has enough conductivity to get you a nasty shock if you have sufficient contact. |
#33
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Conducting concrete
On Thu, 05 Jan 2017 00:12:46 -0000, wrote:
On Wed, 04 Jan 2017 22:22:46 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 22:16:19 -0000, wrote: On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. What part of 20MOhms didn't you understand? Try it and get back to me. That is 20meg at one small point. If you can find 2 pieces of rebar with 20' in contact with the concrete, check that to ground or another rebar in the same slab. Rebar isn't common here, anyway you have to conduct the electricity down to the metal. "Earth" is a pretty bad conductor in the first place so what you are really trying to create is an equipotential ground grid. No it isn't. Earth tends to be damp. Don't tell me you are one of those scotsmen who wear panties. I go commando. Cool, especially when the wind is blowing in off the North Sea in January. ;-) Especially then. I run naked along the beach, which causes amusement. -- Peter is listening to Psy - Gangnam style |
#34
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Conducting concrete
On Thu, 05 Jan 2017 00:14:36 -0000, Dean Hoffman wrote:
On 1/4/17 2:00 PM, James Wilkinson Sword wrote: It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) I guess one doesn't test earth grounding with a regular ohm meter. You guess? The instructor at one of my code refresher classes asked once if anyone had the correct type of tester. No one did out of at least 50 electricians. Earth grounding is primarily for damage from lightning. He also had a diagram showing how little current would flow through the earth if a well motor had a short to the frame. The resistance was so high that there was no way even a tiny fuse would blow if there was a short. This is from the meter maker Fluke: http://support.fluke.com/find-sales/Download/Asset/2633834_6115_ENG_A_W.PDF "A good grounding resistance is 5 ohms or less" - well since I got 20 MOhms, I guess that isn't grounded. -- The longest word in German is DONAUDAMPFSCHIFFAHRTSELEKTRIZITAETENHAUPTBETRIEBSW ERKBAUUNTERBEAMTENGESELLSCHAFT, "the club for subordinate officials of the head office management of the Danube steamboat electrical services" (name of a pre-war club in Vienna), according to 1996 Guinness. |
#35
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Conducting concrete
On Thu, 05 Jan 2017 00:16:53 -0000, wrote:
On Wed, 04 Jan 2017 23:31:13 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 22:56:57 -0000, FromTheRafters wrote: James Wilkinson Sword pretended : On Wed, 04 Jan 2017 22:16:19 -0000, wrote: On Wed, 04 Jan 2017 21:22:56 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:11:26 -0000, wrote: On Wed, 04 Jan 2017 20:00:22 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 19:13:21 -0000, mike wrote: On 1/4/2017 10:48 AM, burfordTjustice wrote: On Wed, 04 Jan 2017 10:42:34 -0800 mike wrote: On 1/4/2017 9:58 AM, James Wilkinson Sword wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Sorry, can't find the post it was mentioned in. Can't help with a link, but I recently replaced my water main with PEX. That broke the ground to the house and wouldn't pass inspection. Long story short, research indicated that using rebar in concrete was a trend in establishing a safety ground. Apparently, there's enough conductive salt and water in concrete to make it work, as long as the concrete sits on the ground and you're not in the desert. Contact resistance is high, but there's a lot of area. I followed the code and installed two ground rods. I did some impedance measurements between the rods and the electrical system ground (before connecting) and determined that the "grounding" was insufficient to do anything more than dissipate static electricity, but the inspector liked it. I'd guess that hooking to the rebar is at least as good. "James Wilkinson Sword" is in the UK...different rules Question wasn't about rules. Was about concrete as a ground. Unlikely it's much different in the UK. It was more about getting an electric shock by standing on the floor of your house while touching something live. This was suggested by someone recently as being a danger. I just measured some concrete to make sure I wasn't being ignorant, and it was off the scale (20MOhms) Across what surface area? Why don't you sit on the concrete floor barr assed and grab a hot wire. Have your widow get back to us. 1cm from electrode to electrode = 20MOhms. That's an INSULATOR. No electricity worth considering is passing at all. Then it should be safe, pull up your kilt, plop down on a concrete floor and grab that wire. What part of 20MOhms didn't you understand? https://engineering.purdue.edu/~conc...hapter%203.pdf So as I said before, it's the water conducting. But your floor really really shouldn't be damp. The Ufer ground is not in the floor, it is in the foundation but your concrete floor still has enough conductivity to get you a nasty shock if you have sufficient contact. 20 MOhms prevents shock. -- Why do they rate a movie "R" for "adult language?" The only people I hear using that language are teenagers. |
#36
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Conducting concrete
On 1/4/17 6:32 PM, James Wilkinson Sword wrote:
Some cut. I guess one doesn't test earth grounding with a regular ohm meter. You guess? The instructor at one of my code refresher classes asked once if anyone had the correct type of tester. No one did out of at least 50 electricians. Earth grounding is primarily for damage from lightning. He also had a diagram showing how little current would flow through the earth if a well motor had a short to the frame. The resistance was so high that there was no way even a tiny fuse would blow if there was a short. This is from the meter maker Fluke: http://support.fluke.com/find-sales/Download/Asset/2633834_6115_ENG_A_W.PDF "A good grounding resistance is 5 ohms or less" - well since I got 20 MOhms, I guess that isn't grounded. So did you use an actual ground tester or a volt/ohm meter? It sure seems odd that your results don't match Mr. Ufer's and bunches of people after him. An article in Electrical Contractor magazine says Ufer's grounding electrodes kept the resistance at 2-5 ohms over a 20 year period. http://www.ecmag.com/section/codes-standards/what-ufer-ground |
#37
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Conducting concrete
On Thu, 05 Jan 2017 01:13:23 -0000, Dean Hoffman wrote:
On 1/4/17 6:32 PM, James Wilkinson Sword wrote: Some cut. I guess one doesn't test earth grounding with a regular ohm meter. You guess? The instructor at one of my code refresher classes asked once if anyone had the correct type of tester. No one did out of at least 50 electricians. Earth grounding is primarily for damage from lightning. He also had a diagram showing how little current would flow through the earth if a well motor had a short to the frame. The resistance was so high that there was no way even a tiny fuse would blow if there was a short. This is from the meter maker Fluke: http://support.fluke.com/find-sales/Download/Asset/2633834_6115_ENG_A_W.PDF "A good grounding resistance is 5 ohms or less" - well since I got 20 MOhms, I guess that isn't grounded. So did you use an actual ground tester or a volt/ohm meter? It sure seems odd that your results don't match Mr. Ufer's and bunches of people after him. An article in Electrical Contractor magazine says Ufer's grounding electrodes kept the resistance at 2-5 ohms over a 20 year period. http://www.ecmag.com/section/codes-standards/what-ufer-ground Resistance is resistance. Concrete does NOT conduct. WATER conducts. Concrete is a porous material which may or may not contain water. The floor of your house should never contain water, or you have BIG problems, way above a possibility of shock. -- "VAT is a simple tax..." -- Anthony Barber, Chancellor of the Exchequer on the introduction of VAT on April Fool's Day in 1973. |
#38
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Conducting concrete
On Thu, 05 Jan 2017 00:13:04 -0000, "James Wilkinson Sword"
wrote: On Thu, 05 Jan 2017 00:05:58 -0000, wrote: On Wed, 04 Jan 2017 22:22:05 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 22:14:30 -0000, wrote: On Wed, 04 Jan 2017 21:11:44 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:04:15 -0000, wrote: On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword" wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp If your floor is damp all the way through, you have bigger problems. Concrete floors are for garages, houses should have wood floors suspended above the ground. What century is the USA living in? One where we have not solved the termite, Chemicals are your friend. Fine when they work and don't migrate to the ground water. Not my problem. hurricane and tornado problems? Those tend to affect walls and roofs. If your floor is off the ground, it will just be part of the debris field when the wind gets up under it. If the walls are gone, why do you care about your floor? Under a decent building code they will all stand or blow away together. The roof is continuously tied through the walls to the foundation In a concrete block building that will be continuous rebar from the foundation to the poured tie beam on the top of the wall, then strapped to the roof trusses. A typical 1800 sq/ft house will have almost 100,000 pounds of uplift protection at the roof. |
#39
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Conducting concrete
On Thu, 05 Jan 2017 01:24:08 -0000, "James Wilkinson Sword"
wrote: On Thu, 05 Jan 2017 01:13:23 -0000, Dean Hoffman wrote: On 1/4/17 6:32 PM, James Wilkinson Sword wrote: Some cut. I guess one doesn't test earth grounding with a regular ohm meter. You guess? The instructor at one of my code refresher classes asked once if anyone had the correct type of tester. No one did out of at least 50 electricians. Earth grounding is primarily for damage from lightning. He also had a diagram showing how little current would flow through the earth if a well motor had a short to the frame. The resistance was so high that there was no way even a tiny fuse would blow if there was a short. This is from the meter maker Fluke: http://support.fluke.com/find-sales/Download/Asset/2633834_6115_ENG_A_W.PDF "A good grounding resistance is 5 ohms or less" - well since I got 20 MOhms, I guess that isn't grounded. So did you use an actual ground tester or a volt/ohm meter? It sure seems odd that your results don't match Mr. Ufer's and bunches of people after him. An article in Electrical Contractor magazine says Ufer's grounding electrodes kept the resistance at 2-5 ohms over a 20 year period. http://www.ecmag.com/section/codes-standards/what-ufer-ground Resistance is resistance. Concrete does NOT conduct. WATER conducts. Concrete is a porous material which may or may not contain water. The floor of your house should never contain water, or you have BIG problems, way above a possibility of shock. Stop the presses, some naked scotsman has debunked 100 years of electrical science. Your Nobel prize is in the mail sir. |
#40
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Conducting concrete
On Thu, 05 Jan 2017 01:32:03 -0000, wrote:
On Thu, 05 Jan 2017 00:13:04 -0000, "James Wilkinson Sword" wrote: On Thu, 05 Jan 2017 00:05:58 -0000, wrote: On Wed, 04 Jan 2017 22:22:05 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 22:14:30 -0000, wrote: On Wed, 04 Jan 2017 21:11:44 -0000, "James Wilkinson Sword" wrote: On Wed, 04 Jan 2017 21:04:15 -0000, wrote: On Wed, 04 Jan 2017 17:58:12 -0000, "James Wilkinson Sword" wrote: Somebody in one of these two groups recently said that a concrete based house means you're earthed. Concrete is a bloody good insulator! Not really true, particularly if it is damp If your floor is damp all the way through, you have bigger problems. Concrete floors are for garages, houses should have wood floors suspended above the ground. What century is the USA living in? One where we have not solved the termite, Chemicals are your friend. Fine when they work and don't migrate to the ground water. Not my problem. hurricane and tornado problems? Those tend to affect walls and roofs. If your floor is off the ground, it will just be part of the debris field when the wind gets up under it. If the walls are gone, why do you care about your floor? Under a decent building code they will all stand or blow away together. The roof is continuously tied through the walls to the foundation In a concrete block building that will be continuous rebar from the foundation to the poured tie beam on the top of the wall, then strapped to the roof trusses. A typical 1800 sq/ft house will have almost 100,000 pounds of uplift protection at the roof. I see. We don't have so much wind here, so my next question is, why are modern houses in the UK starting to have concrete foundations like yours? Old ones, you go under the floor, you can crawl around on dirt and fix the pipes and wires. New ones, you can't get down, it's just solid. -- Computers can never replace human stupidity. |
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