Jump to content

Connecting ground wire.


fred42

Recommended Posts

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.

  • Like 3
Link to post
Share on other sites
  • Replies 58
  • Created
  • Last Reply

Top Posters In This Topic

  • ShawnM

    8

  • Headshot

    7

  • fred42

    6

  • Mikala

    5

Top Posters In This Topic

Popular Posts

Let a lineman do it. It won't cost you much, and I don't want to lose a friend. There is a rule in line work. You always connect the neutral first...and then the hot legs. When you disconnect, you dis

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 sti

Better to talk with a local lineman (either VECO or contractor) when you see them out working and get him to do it on the side (for a fee of course). It isn't something that can be done hot, and the o

Posted Images

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

 

Link to post
Share on other sites
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.   

Link to post
Share on other sites
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

 

  • Like 1
Link to post
Share on other sites
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.

  • Like 1
Link to post
Share on other sites
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.

Link to post
Share on other sites

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.

Link to post
Share on other sites
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..

Link to post
Share on other sites
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
  • Like 1
Link to post
Share on other sites
SkyMan

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

  • Like 1
Link to post
Share on other sites
Mikala

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

 

I'd go with what Headshot recommended. You don't want much distance between yourself and the grounds. Saving a few pesos isn't worth someone's life.

  • Like 1
Link to post
Share on other sites
SkyMan

I'd go with what Headshot recommended. You don't want much distance between yourself and the grounds. Saving a few pesos isn't worth someone's life.

How do you know how far it is to the pole or the septic tank for that matter?  I wouldn't put the septic any closer than I had to so the pole might be the closer of the too.  And with the pole, you don't have to worry about the ground drying out or is my copper rod deep enough, etc.

Link to post
Share on other sites
Mikala

How do you know how far it is to the pole or the septic tank for that matter?  I wouldn't put the septic any closer than I had to so the pole might be the closer of the too.  And with the pole, you don't have to worry about the ground drying out or is my copper rod deep enough, etc.

 

Sorry, I didn't read thru all the previous posts. A combination of what has been previously written would be the safest. If there's only going to be 1 ground, then what Headshot wrote would be very good. A poster afterwards recommended using 4 stainless steel rods, but those might be cost-prohibitive.

 

What's referred to as a copper ground rod is just a copper coated steel rod. These corrode easily in a wet environment and over a period of years, you will lose your grounding. My experience in Hawaii is that we'd always recommend customers install at least 2 ground rods in an attempt to make the home safe for a few decades. On my ranch, I have soil that's about 4 meters deep. I used 4 ground rods (minimum 2 meters apart), but I could push the rods in with my hand most of the way.

 

Note: these ground rods are also tied together to provide lightning protection.

 

Oh, utility pole ground rods are usually driven in close to the pole itself (made out of wood). That lowers its ability to dissipate any electrical energy. The utility's ground rod also should not be used as it's usually considered the property of the utility.

Link to post
Share on other sites
Headshot

The grounds on most poles here are only connected to the communications cables, so they don't provide any tie to the power system. You can establish a grounded neutral at a transformer (where voltage is stepped up or down), but not independent of a transformer. Unfortunately, though the center points on transformers are generally grounded here, there is no neutral established (that is run to the house). That is why we have 220 volt secondary here rather than 110/220 volt secondary.

 

In the US, we are used to having a grounded neutral run into the home, which gives us stable voltage. Here, because we only have the two hot legs with no neutral, the voltage isn't nearly as stable. Do not confuse running ground wires along with the power wires with having a neutral wire that can be connected to form a circuit. The only place the ground wire can be connected is to the grounding point on outlets (the third hole...if there is one).

 

Because most homes have no grounding here, it is rare to see outlets with grounding holes (a third hole). Most outlets here only have two holes for the power prongs of plugs. When I had my house remodeled, I had a central ground driven, which is connected to a bar in the breaker box, which is in turn connected to the ground wires for all circuits in the house. That allows me to use things like surge protectors. Without a ground, they won't function, and therefore offer no protection. Any time you break off the ground prong on a surge protector cable (or use an adapter) to allow it to be plugged into a two-hole outlet, you turn it into a simple extension cord.

Edited by Headshot
  • Like 2
Link to post
Share on other sites
David_LivinginTalisay

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).

 

ELCB's have largely been replaced with RCD's in the UK.

 

 
History

ELCBs were mainly used on TT earthing systems. Nowadays, ELCBs have been mostly replaced by residual-current devices(RCDs). However many ELCBs are still in use.

Early ELCBs responded to sine wave fault currents, but not to rectified fault current. Over time, filtering against nuisance trips has also improved. Early ELCBs thus offer a little less safety and higher risk of nuisance trip. The ability to distinguish between a fault condition and non-risk conditions is called discrimination.

 

 

 

residual-current device (RCD), or residual-current circuit breaker (RCCB) or residual twin-direct current couplet (R2D2), is an electrical wiring device that disconnects a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor. Such an imbalance may indicate current leakage through the body of a person who is grounded and accidentally touching the energized part of the circuit. A lethal shock can result from these conditions. RCCBs are designed to disconnect quickly enough to prevent injury caused by such shocks. They are not intended to provide protection against overcurrent (overload) or all short-circuit conditions.

In the United States and Canada, a residual-current device is most commonly known as a Ground Fault Circuit Interrupter (GFCI), Ground Fault Interrupter (GFI) or an Appliance Leakage Current Interrupter (ALCI). Ground Fault Condition is defined as: An unintentional, electrically conducting connection between an ungrounded conductor of an electrical circuit and the normally non-current-carrying conductors, metallic enclosures, metallic raceways, metallic equipment or earth.

In the United Kingdom, a residual-current device is referred to as an RCD or an RCBO when including overcurrent protection. Non residual-current circuit protection devices are called Circuit Breakers or MCBs. Infrequently they can be called Trips or Trip Switches.

In Australia, they are sometimes known as Safety Switches or an RCD.

residual-current circuit breaker with overload protection (RCBO) combines the functions of overcurrent protection and leakage detection. An earth leakage circuit breaker (ELCB) may be a residual-current device, although an older type of voltage-operated earth leakage circuit breaker exists.

Residual-current device is a generic term covering both RCCBs and RCBOs.

 

Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use, Privacy Policy and Guidelines. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue..