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fred42

Connecting ground wire.

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fred42

As we have land on a pretty much solid limestone we are having problems driving in the ground bar..

Ive just been doing a bit of reading about "Ufer ground" which is basically connecting the ground wire to the foundations..

http://en.wikipedia.org/wiki/Ufer_ground

Cant do that as no exposed rebar now..

Would connecting the ground wire to the rebar in the underground water tank be OK?

The tank is concrete rebar reinforced.

Edited by fred42

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Brucewayne

Two words, mason bit.

Drill the hole deep as possible and cement around the ground rod.

 

I almost forgot, never hook into a water pipe or drain, someone could be electrocuted if there is a short or thunderstorm.

Edited by Brucewayne
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I <3 Cebu

Yeah dont connect earths to any infrastructure, gonna have to drill brah

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fred42

But to avoid drilling if I can...

I was thinking of a hollow block 15"x15" petition inside the septic tank in corner and packing in soil to cover the rod to the top.. That should be OK right? Tank is under construction now.

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RogerDat

Greetings! What do you own that has a ground wire on it?

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sperry

Why cant you connect to any infrastructure?

 

Where does the earth "stop" and the infrastructure "begin"?

 

a good example why you want an earth is a surge suppressor. Many will not work without a ground, that excess power has to go somewhere.

 

if your septic tank is being built, simply run a reasonable diameter copper cable around the tank and back fill with soil. no need for a rod I would have thought. i wouldnt put it in the septic tank itself,

 

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samatm

 

 

I almost forgot, never hook into a water pipe or drain, someone could be electrocuted if there is a short or thunderstorm.

\

 

Really.  our shower heater is grounded to the outside water drain pipe now... better change that.  Thanks

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Mikala

We allow the "ufer" ground in Hawaii, but it does get planted into the earth thru the rebar at some point. Customers complain that the lava and basalt rock is too hard to get a ground into, but we still require the ground for the customer's safety. We even started using equipment to check customer grounds to ensure they were correctly installed.

 

I'd recommend drilling into the ground, but try to get at least 2 to 3 meters into the ground with 2 ground rods. Alternatively you could use a coil of wire around an underground tank (septic?).

 

Keep in mind that corrosion will eat away at whatever ground rod or wire that you're using.

 

Note: cement / concrete is more of an insulator than a conductor. Don't allow any concrete get between your ground rod (or wire) and the earth.

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fred42

Greetings! What do you own that has a ground wire on it?

 

 

We made sure that the whole building was wired live neutral earth..

 

 

Alternatively you could use a coil of wire around an underground tank (septic?).

 

Thanks for the suggestions re septic tank(What size copper wire? No 8 mains wire?) although I have been reading today that concrete is an excellent conductor!! 

Now I`m confused again! 

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fred42

 

 

Why cant you connect to any infrastructure?   Where does the earth "stop" and the infrastructure "begin"?   a good example why you want an earth is a surge suppressor. Many will not work without a ground, that excess power has to go somewhere.  

 

Thats what I was thinking.. There`s a ton of rebar in my  water tank all connected together and in the ground.. Of course its cased in concrete which someone says is an insulator but others that say its almost better than soil as a conductor.

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sperry

We made sure that the whole building was wired live neutral earth..

 

 

Thanks for the suggestions re septic tank(What size copper wire? No 8 mains wire?) although I have been reading today that concrete is an excellent conductor!! 

Now I`m confused again! 

 

um i dont know. When I did it in Europe i used "earth" wire, which is quite thick.

 

remember it has to be unsheathed 9ie not covered in pplasttic so I doubt if you will have much choice. its fairly specailised. if i remember it correctly, it was trssed from around 3 13 amp cables wires to give u some idea

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Mikala

Thats what I was thinking.. There`s a ton of rebar in my water tank all connected together and in the ground.. Of course its cased in concrete which someone says is an insulator but others that say its almost better than soil as a conductor.

Electric Power Research Institute (EPRI) in the USA performed studies for utility pole lightning arrestor grounds. Typically we'd toss a loop of copper wire into the hole (6 AWG solid bare copper wire), then set the pole in concrete. We changed our procedure after the study showed that the concrete was a bad idea. Now using a separate hole for ground rods.

 

Just using common sense, what part of concrete's makeup would make someone think it would conduct electricity? Sand? Cement? Aggregate? I'm surprised it required a study to figure that out! Might as well fund a study if men find beautiful girls more attractive than a dead giraffe...

Edited by Mikala
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Headshot

We made sure that the whole building was wired live neutral earth..

 

 

Thanks for the suggestions re septic tank(What size copper wire? No 8 mains wire?) although I have been reading today that concrete is an excellent conductor!! 

Now I`m confused again! 

 

Nix the idea on just laying wire in the ground. In alkaline soil (which limestone is), any metal you put in the ground WILL corrode...the smaller the diameter, the faster it will corrode. Go the extra mile and lay a ground rod in the ground as deep as you can when you dig the hole for the septic tank. That should be connected to a #6 solid copper wire (don't use stranded wire...which is just a collection of small wires that will each corrode individually). Also nix any thought of hooking the ground to rebar that will be encased in concrete. Though concrete is conductive when wet, once it dries it is highly insulative...and you won't have a good ground.

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lopburi3

It is the re-bar doing the conduction down to water level and the impurities (minerals) in the water that then take over - and water does enter normal concrete.  So yes do not use for slab type construction as you probably have there and above water level but here in Thailand where the water level is normally just below the surface and building piles are used it is sometimes used.  Anything in better than nothing but agree get a good ground and use it.  But even more important is to have ELCB protection (which does not require a ground to work).

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I <3 Cebu

Why cant you connect to any infrastructure?

 

Where does the earth "stop" and the infrastructure "begin"?

 

a good example why you want an earth is a surge suppressor. Many will not work without a ground, that excess power has to go somewhere.

 

if your septic tank is being built, simply run a reasonable diameter copper cable around the tank and back fill with soil. no need for a rod I would have thought. i wouldnt put it in the septic tank itself,

Electrolysis, electric shock, etc.

 

I'm not a sparky but ran heaps of earth's for various things. We never connected it to something that a person would go near (infrastructure we call it). Current always seeks ground & takes the easiest path.

A common process was 4 stainless stakes 1.2m deep with a wire hoop about 300mm deep & often a 5th placed a few meters away.

 

For homes,from what ive seen they just have a copper stake below the meter box. Must be good enough for 240v

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Headshot

It is the re-bar doing the conduction down to water level and the impurities (minerals) in the water that then take over - and water does enter normal concrete.  So yes do not use for slab type construction as you probably have there and above water level but here in Thailand where the water level is normally just below the surface and building piles are used it is sometimes used.  Anything in better than nothing but agree get a good ground and use it.  But even more important is to have ELCB protection (which does not require a ground to work).

 

You are assuming the bottom of the concrete is below the water table. If that is the case, he has chosen his building site very poorly. Besides. he is talking about building on rock (he can't drive a ground rod), so having the water table anywhere close is very unlikely. I did 15 years as an electrical distribution standards engineer. Trust me when I say that rebar in concrete will NOT provide a good long-term ground. We tested many of them, and they always gave a high ohm reading (sign of a bad ground) after five to ten years from installation.

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For Real

 

Really. our shower heater is grounded to the outside water drain pipe now... better change that. Thanks

event the ungrounded units fail. Had a nice tickle from the shower nozzle, luckily before the water was on...if you must use one of those death traps instead of room temp water use a rubber hose dude.

 

 

 

Sent from my iPad using Tapatalk

 

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samatm

event the ungrounded units fail. Had a nice tickle from the shower nozzle, luckily before the water was on...if you must use one of those death traps instead of room temp water use a rubber hose dude.

 

 

 

Sent from my iPad using Tapatalk

Sorry I don't quite follow you.   

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For Real

Sorry I don't quite follow you.

ok.

The wall mounted electric water heaters (I guess from china) short. My experience was getting a 220 volt belt when grabbing the shower nozzle off the wall hook. Metal hose, metal nozzle made me a circuit. I still have one but it's disconnected...if I would connect for a visitor I'd get a rubber/plastic hose nozzle to connected to the hot water outlet.

 

 

Sent from my iPad using Tapatalk

 

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lopburi3

 

 

You are assuming the bottom of the concrete is below the water table. If that is the case, he has chosen his building site very poorly.

Actually I was not assuming any such thing and stated it likely was not a good option - I am saying in Thailand with the normal 15 meter or more piles used for support in the mud and below water line and the only option (as when renting an apartment or condo, it is better than nothing.

 

But admit my wording was poor with the "So yes do not use".  Sorry for that.

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lopburi3

 

 

event the ungrounded units fail. Had a nice tickle from the shower nozzle, luckily before the water was on...if you must use one of those death traps instead of room temp water use a rubber hose dude.

 

The wall mounted electric water heaters (I guess from china) short. My experience was getting a 220 volt belt when grabbing the shower nozzle off the wall hook. Metal hose, metal nozzle made me a circuit. I still have one but it's disconnected...if I would connect for a visitor I'd get a rubber/plastic hose nozzle to connected to the hot water outlet.

That should not happen if there is the normal ELCB built into the unit - however did have a mechanical blockage on a US brand name some years ago that prevented breaker trip - which was modified in later models.  Best to also have a ground as that will allow faster trip of main breaker as well as case/run before ELCB breaker.

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sperry

It is the re-bar doing the conduction down to water level and the impurities (minerals) in the water that then take over - and water does enter normal concrete.  So yes do not use for slab type construction as you probably have there and above water level but here in Thailand where the water level is normally just below the surface and building piles are used it is sometimes used.  Anything in better than nothing but agree get a good ground and use it.  But even more important is to have ELCB protection (which does not require a ground to work).

 

i would agree with that especially in a condominium. even if dry concrete is a bad conductor, in the wet climate of cebu i doubt if concrete stays that dry

and with the poor waste water run off here im sure im sure the ground is pretty damp. a lot of the concrete certianly looks as though it has water damage.

 

also the rebar in a large condo building will have a huge surface area for conducting into the concrete above and below ground level, so i reckon attaching a cable to the rebar is probably a lot better than nothing.

 

and for fwiw when i installed the elcetrics on the house i had built in europe

 

it was manadatory to connect the copper water pipes to the earth

recommended earth for new build was to string a cable in the trench around the house rather than use a metal stake hamered in to the ground.

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fred42
You are assuming the bottom of the concrete is below the water table.

 

 

Our water tank is about 2 feet below the high tide level.. we know this as when we dug the hole 2.5 meters deep the sea came in at high tide..

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Brucewayne

Electric Power Research Institute (EPRI) in the USA performed studies for utility pole lightning arrestor grounds. Typically we'd toss a loop of copper wire into the hole (6 AWG solid bare copper wire), then set the pole in concrete. We changed our procedure after the study showed that the concrete was a bad idea. Now using a separate hole for ground rods.

 

Just using common sense, what part of concrete's makeup would make someone think it would conduct electricity? Sand? Cement? Aggregate? I'm surprised it required a study to figure that out! Might as well fund a study if men find beautiful girls more attractive than a dead giraffe...

 Makes sense since sand is silica, which is used to make glass and glass insulators.

Edited by Brucewayne
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SkyMan

Any chance you can connect to the ground on the pole?

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