Breaker Box Wiring

[chownah]

Elkangorito,

Yes, I will have two meters and two panels and two electic bills...and, of course the new panel will have a ground electrode to meet the local reqirements just like all panels have...it will be, afterall a new service. The only thing unusual which I will be doing is running circuits from this new service into a house that has wiring already from another service...and I will be careful to keep them totally seperated electrically. Thank you for your input.

Chownah

[dougkos]

Elkangorito,

Yes, I will have two meters and two panels and two electic bills...and, of course the new panel will have a ground electrode to meet the local reqirements just like all panels have...it will be, afterall a new service. The only thing unusual which I will be doing is running circuits from this new service into a house that has wiring already from another service...and I will be careful to keep them totally seperated electrically. Thank you for your input.

Chownah

hi guys

thought i would make a post regarding this topic, i agree with crossy and elkangorito on a lot of the issues raised.

Chowan- in regards to suppling a ground/earth wire to your sockets it has got to be done there was a directive saying from Oct 2003 you had to supply it. http://www.copper.org.sg/pdf/BW%20Brochure...(20030519)1.pdf

what height are your poles at? is it insulated cables you have installed or bare wires?

dougie

Oh dear!! What have we here?

Ok Chownah, your idea is ok but how it is implemented, is another matter.

I'm assuming, from what you have said, that you will have 2 "SEPARATELY METERED SUPPLIES". If this is incorrect, please say so. Allow me to explain...if you have 2 separate supplies coming into your property, they SHOULD be treated as 2 separate installations with individual meters thus you will receive 2 power bills...one for each installation. Is this correct?

If not, then the power to your NEW installation MUST come from your Main Distribution Board as a "sub circuit".

Also, IF the new installation is a separate supply, then an MEN link MUST be installed in this new installation.

Further, as Crossy said, if you experience dimming of lights etc when motors cut in, then you need "fatter" cables. This is a direct consequence of voltage drop due to long distance of cables with maximum current demand. Basically, this means that the cable size from the transformer is not big enough for your requirements. As an example & contrary to Lopburi's ideas, 3 phase supply is available if you give a reason. A mate of my'n got 3 phase supply because he was using 3 phase motors for a fish/prawn farm. The supply authority installed a 3 phase 50mm squared (aluminium) supply as a result of his request. I dare say that he had to prove his requirement. Nonetheless, he has a large amount of power at his disposal. I do not know anything about this 5/15 or 15/45 amp meter stuff. What the he_l does it mean? Normally, supply is indicated by demand current. ie an 80 amp supply is fed by minimum 16mm squared copper aerial conductors. The kwH meter reflects the cable size. In Thailand, it may be different & until someone can give me some diffinitive information about this, I will not think otherwise. Kilowatt hour meters are rated for their "through put" current, since they are in series with the line current. So, what does 5/15 mean? By the way, unless this can be answered with "provable" information, I will not believe it.

With regard to "poles", they are not the issue. The issue is cable size. Bamboo is ok. It just degrades very quickly due to ingress of ants etc. If they have appropritae electrical insulators upon them, all is ok untill nature quickly degrades them.

Anyway, if you plan to foolishly apply an earthless installation, GOOD LUCK!!! I will never endorse this.

Just going back to a previous statement, YOU MUST HAVE AN MEN SYSTEM INSTALLED AS A "PRIMARY" SAFETY SYSTEM. Without this, you & your family are at a much greater risk of electrocution. Don't forget that the SECONDARY SYSTEM is an RCD (earth leakage protection device). If you've read the previous posts, you will know the dangers of relying totally upon the "RCD only" system. I will be happy to reiterate should you have forgotten.

EATHING IS THE MOST IMPORTANT THING YOU MUST DO. THIS INCLUDES ALL METAL CLAD APPLIANCES. DOUBLE INSULATED APPLIANCES LIKE TV'S ARE NOT A PROBLEM. YOU MUST USE 3 PIN POWER OUTLETS. IF IN DOUBT, EARTH IT!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

hi elkangorito

I think what is being refered here regarding the 5/15amp etc is down to the consumer tariffs, the consumer gets what he can afford (or thinks he can)

http://www.pea.co.th/eweb/r_rate1.htm

hope this clears up some things

dougie

[chownah]

".................

Chowan- in regards to suppling a ground/earth wire to your sockets it has got to be done there was a directive saying from Oct 2003 you had to supply it. http://www.copper.org.sg/pdf/BW%20Brochure...(20030519)1.pdf

..........."

I checked out your link and it seems to be some promotional material for a company whose head office is in Singapore. I didn't read it all but it doesn't appear to have anything to do with the electrical wiring requirements in Thailand....or was your comment actually just a joke.?

[dougkos]

sukit.ppt

".................

Chowan- in regards to suppling a ground/earth wire to your sockets it has got to be done there was a directive saying from Oct 2003 you had to supply it. http://www.copper.org.sg/pdf/BW%20Brochure...(20030519)1.pdf

..........."

I checked out your link and it seems to be some promotional material for a company whose head office is in Singapore. I didn't read it all but it doesn't appear to have anything to do with the electrical wiring requirements in Thailand....or was your comment actually just a joke.?

hi

if you scrolled down to page 4 on fig.2 you would see where it is mentioned, there is another link regarding it i had seen before thought i had saved it on my comp. still trying to search for it.

the home page of copper is http://www.copper.org.sg/publications/publications_list.html

have a look at it.

why would you think i was making a joke?

have a look at the attachment this is what you are meant to do during your installation and after

[lopburi3]

Perhaps because of the recent talk of Singapore buying Thailand?

[chownah]

sukit.ppt

".................

Chowan- in regards to suppling a ground/earth wire to your sockets it has got to be done there was a directive saying from Oct 2003 you had to supply it. http://www.copper.org.sg/pdf/BW%20Brochure...(20030519)1.pdf

..........."

I checked out your link and it seems to be some promotional material for a company whose head office is in Singapore. I didn't read it all but it doesn't appear to have anything to do with the electrical wiring requirements in Thailand....or was your comment actually just a joke.?

hi

if you scrolled down to page 4 on fig.2 you would see where it is mentioned, there is another link regarding it i had seen before thought i had saved it on my comp. still trying to search for it.

the home page of copper is http://www.copper.org.sg/publications/publications_list.html

have a look at it.

why would you think i was making a joke?

have a look at the attachment this is what you are meant to do during your installation and after

I did find it, thank you very much. I'll ask the local electrical administration and see if this applies to my village.

[dougkos]

sukit.ppt

".................

Chowan- in regards to suppling a ground/earth wire to your sockets it has got to be done there was a directive saying from Oct 2003 you had to supply it. http://www.copper.org.sg/pdf/BW%20Brochure...(20030519)1.pdf

..........."

I checked out your link and it seems to be some promotional material for a company whose head office is in Singapore. I didn't read it all but it doesn't appear to have anything to do with the electrical wiring requirements in Thailand....or was your comment actually just a joke.?

hi

if you scrolled down to page 4 on fig.2 you would see where it is mentioned, there is another link regarding it i had seen before thought i had saved it on my comp. still trying to search for it.

the home page of copper is http://www.copper.org.sg/publications/publications_list.html

have a look at it.

why would you think i was making a joke?

have a look at the attachment this is what you are meant to do during your installation and after

I did find it, thank you very much. I'll ask the local electrical administration and see if this applies to my village.

hi chowan

ur welcome, if your village falls under the PEA auth. then it should apply

http://www.copper.org.sg/publications/spot...003/story1.html

if you have time go into copper home page look in our publications click on "spotlight" look at the back issues regarding the different topics but mainly on earthing/grounding.

[elkangorito]

Everybody,

All this information is well & good providing that one has ONE "standard" upon which to base it. THIS IS VERY IMPORTANT!!! DO NOT MIX STANDARDS!!!!

Also, it appears, from the info that dougkas has provided, that the current rating of kilowatt hour meters is more to do with your tarriffs than the current rating of the meter. I think this system will (hopefully) fade fast in Thailand. Sensibly, kilowatt hour meters are not chosen for the tarriff...they are chosen based upon the current rating of the installations supply current. In most places in the world, a supply is issued in accordance to "standard" demand ie 80 amps in Australia. Therefore, the kilowatt hour meter used in Australia, is capable of handling a "through" current of 80 amps. Consequently, I still do not understand the 15/45 rating of Thai meters. Does it mean a tarriff of no greater than 15 amp but a possible max current of 45 amps? Can somebody help me to "definitively" clear up this point?

Chownah, please do not forget that if you are going to use two separate supplies, that you must have a separate MEN link for each supply, which shall be installed into the Main Distribution Board of each installation.

Again, the most important conductor is the EARTH conductor, the 2nd most important conductor is the Neutral conductor & the least important conductor is the Active.

Don't forget, the MEN system of earthing is the PRIMARY DEFENSE against electrical shock. The secondary defense is an RCD...USED IN CONJUNCTION WITH A PROPERLY EARTHED INSTALLATION!!!!. You will be foolish to rely solely upon RCD's to protect you & your loved ones.

[lopburi3]

I believe the meter used here is either the same or very similar to the glass enclosed RMM 230 (3 wire version) shown on http://www.dmmetering.com/.

((click Mechanical meters - single phase))

As for the 15 amps believe that is average power use and 45 amps is peak power use but have not seen that on paper. So if you were using more than about 80 KWH per day (average) on the 15/45 meter they would recommend a larger meter/service.

[dougkos]

Everybody,

All this information is well & good providing that one has ONE "standard" upon which to base it. THIS IS VERY IMPORTANT!!! DO NOT MIX STANDARDS!!!!

Also, it appears, from the info that dougkas has provided, that the current rating of kilowatt hour meters is more to do with your tarriffs than the current rating of the meter. I think this system will (hopefully) fade fast in Thailand. Sensibly, kilowatt hour meters are not chosen for the tarriff...they are chosen based upon the current rating of the installations supply current. In most places in the world, a supply is issued in accordance to "standard" demand ie 80 amps in Australia. Therefore, the kilowatt hour meter used in Australia, is capable of handling a "through" current of 80 amps. Consequently, I still do not understand the 15/45 rating of Thai meters. Does it mean a tarriff of no greater than 15 amp but a possible max current of 45 amps? Can somebody help me to "definitively" clear up this point?

Chownah, please do not forget that if you are going to use two separate supplies, that you must have a separate MEN link for each supply, which shall be installed into the Main Distribution Board of each installation.

Again, the most important conductor is the EARTH conductor, the 2nd most important conductor is the Neutral conductor & the least important conductor is the Active.

Don't forget, the MEN system of earthing is the PRIMARY DEFENSE against electrical shock. The secondary defense is an RCD...USED IN CONJUNCTION WITH A PROPERLY EARTHED INSTALLATION!!!!. You will be foolish to rely solely upon RCD's to protect you & your loved ones.

hi

I agree with you elkangorito regarding 1 standard,the info I have supplied is from PEA via the "copper" org http://www.copper.org.sg/publications/spot...003/story1.html

regarding earthing/grounding.

I dont think that the tariff system with the 5 amps will change its all to do with what the consumer can afford to pay, it happens a lot in 3rd world countries, in zimbabwe we restricted the consumer by means of a load limiter (mcb) different amp sizes and he paid a fixed monthly sum accordingly, if he tried to put on extra load the mcb would trip, we never installed meters thou.

tried to find out about the 15/45 nothing so far, I would rather say its 5-upwards until the auth says you need a 3 phase supply (not sure thou)

dougie

[Gary A]

I have followed this thread and found for the most part that I'm not smart enough to understand a lot of what has been discussed. If you are living in a house you can be safe easily by using the copper plated ground (earth) rods. Try to find a place near the house that stays damp and drive the rod in the ground there. This serves two purposes. It is much easier to pound the rod into damp ground and the rod will get a much better gound. Since I didn't want to string the ground wire through the whole house I use several ground rods.

[Crossy]

Since I didn't want to string the ground wire through the whole house I use several ground rods.

Using several ground rods that are NOT bonded together electrically can result in hazardous voltages between the different 'grounds'. Please be aware of this fact!

Such an installation contravenes UK and international standards (BS7671 [iEE Wiring Regulations 16th Edition] and IEC 60364) and probably Thai standards too (if we can ever actually locate a Thai standard that is).

As others have said, the ground is the single most important conductor in your installation.

[Gary A]

Since I didn't want to string the ground wire through the whole house I use several ground rods.

Using several ground rods that are NOT bonded together electrically can result in hazardous voltages between the different 'grounds'. Please be aware of this fact!

Such an installation contravenes UK and international standards (BS7671 [iEE Wiring Regulations 16th Edition] and IEC 60364) and probably Thai standards too (if we can ever actually locate a Thai standard that is).

As others have said, the ground is the single most important conductor in your installation.

All I know for sure is that grounding the chassis of the appliance that was shocking me took care of the problem.

[Crossy]

All I know for sure is that grounding the chassis of the appliance that was shocking me took care of the problem.

What you have is, of course, infinitely safer than nothing

Under normal circumstances there will be a very small potential between your ground stakes, the problems occur under fault conditions (not necessarily faults in your building) where large ground currents are flowing. It is not unknown for livestock to be killed by the potential between the front and back legs when they happened to be in the wrong place at the wrong time, so you can see that it's not piddling little voltages.

All I am saying is be aware of the potential potential

[elkangorito]

All I know for sure is that grounding the chassis of the appliance that was shocking me took care of the problem.

What you have is, of course, infinitely safer than nothing

Under normal circumstances there will be a very small potential between your ground stakes, the problems occur under fault conditions (not necessarily faults in your building) where large ground currents are flowing. It is not unknown for livestock to be killed by the potential between the front and back legs when they happened to be in the wrong place at the wrong time, so you can see that it's not piddling little voltages.

All I am saying is be aware of the potential potential

Crossy, I agree with you 2000%

However, even though multiple earths are better than none & as you said, this situation can lead to dangerous earth potentials between earth stakes. As a consequence, I think it is a bad idea to endorse multiple earths.

Gary A, the only safe & acceptable method of eathing a residential installation is as follows;

1) Only 1 (one) main earth stake shall be used.

2) The copper used shall be of "electrical" quality (usually 98%+ copper).

3) The earth stake shall be of a minimum length of 1 (one) metric metre & shall be driven into the ground to a depth of no less than 600mm, although the longer the better & the deeper the better. Damp soil is not required or all that important. The most important thing here, is to place the earth stake as close as possible to the Main Distribution Board.

4) The earth stake can be of the "copper sheathed/steal core" type, which makes it easier to be driven into the ground.

5) In a single phase installation, the size of the cable from the earth stake to the Main Distribution Board, shall be the same size as the largest "active" conductor. In a 3 phase installation, the size of the cable from the earth stake to the Main Distribution Board, shall be at least half the size of the largest "active" conductor.

6) The earth cable shall be "mechanically bonded" to the earth stake by an appropriate clamp & then this connection shall be painted with Acrylic paint. The paint prevents oxidisation.

7) The Main Earth cable shall be DIRECTLY connected (no breaks or other connections) to the Main Earth Bar, which is inside the Main Distribution Board.

8) All GPO's (power points) shall be earthed & the earth cable for each GPO circuit shall be terminated at the Main Earth Bar.

9) A cable the same size as the largest "active" conductor, shall connect the Main Earth Bar to the Main Neutral Bar (this is the MEN link), within the Main Distribution Board only.

10) All appliances that are NOT "double insulated" (ie metal clad, like fridges etc), shall have their chassis earthed through their connecting GPO.

11) The main earth connection (at the stake) shall be accessible at all times & shall be mechanically protected against damage. (don't upset it in any way).

I hope this is not too confusing.

Edited February 23, 2006 by elkangorito

[Crossy]

elkangorito

Not really my intention to 'endorse' the use of multiple earth stakes, just make Gary aware of the potential dangers of his installation.

Interestingly both BS7671 [iEE Wiring Regulations 16th Edition] and IEC 60364 PERMIT (or actively endorse) the use of multiple earth stakes PROVIDED they are all connected directly to the main equipotential earth bar in the consumer unit / breaker box, giving a single earth point for all equipment in the building.

You are already aware of my (and the IEE's) position on the use of MEN links in installations fed by overhead lines with their inherent risk of open circuit neutral conductors (and the resultant rise of the earth line to near phase voltage). We agree to differ on this point

I concur 100000% with everything else you say.

Just out of interest, did you train in Oz?

Edited February 23, 2006 by Crossy

[chownah]

All I know for sure is that grounding the chassis of the appliance that was shocking me took care of the problem.

What you have is, of course, infinitely safer than nothing

Under normal circumstances there will be a very small potential between your ground stakes, the problems occur under fault conditions (not necessarily faults in your building) where large ground currents are flowing. It is not unknown for livestock to be killed by the potential between the front and back legs when they happened to be in the wrong place at the wrong time, so you can see that it's not piddling little voltages.

All I am saying is be aware of the potential potential

Crossy, I agree with you 2000%

However, even though multiple earths are better than none & as you said, this situation can lead to dangerous earth potentials between earth stakes. As a consequence, I think it is a bad idea to endorse multiple earths.

Gary A, the only safe & acceptable method of eathing a residential installation is as follows;

1) Only 1 (one) main earth stake shall be used.

2) The copper used shall be of "electrical" quality (usually 98%+ copper).

3) The earth stake shall be of a minimum length of 1 (one) metric metre & shall be driven into the ground to a depth of no less than 600mm, although the longer the better & the deeper the better. Damp soil is not required or all that important. The most important thing here, is to place the earth stake as close as possible to the Main Distribution Board.

4) The earth stake can be of the "copper sheathed/steal core" type, which makes it easier to be driven into the ground.

5) In a single phase installation, the size of the cable from the earth stake to the Main Distribution Board, shall be the same size as the largest "active" conductor. In a 3 phase installation, the size of the cable from the earth stake to the Main Distribution Board, shall be at least half the size of the largest "active" conductor.

6) The earth cable shall be "mechanically bonded" to the earth stake by an appropriate clamp & then this connection shall be painted with Acrylic paint. The paint prevents oxidisation.

7) The Main Earth cable shall be DIRECTLY connected (no breaks or other connections) to the Main Earth Bar, which is inside the Main Distribution Board.

8) All GPO's (power points) shall be earthed & the earth cable for each GPO circuit shall be terminated at the Main Earth Bar.

9) A cable the same size as the largest "active" conductor, shall connect the Main Earth Bar to the Main Neutral Bar (this is the MEN link), within the Main Distribution Board only.

10) All appliances that are NOT "double insulated" (ie metal clad, like fridges etc), shall have their chassis earthed through their connecting GPO.

11) The main earth connection (at the stake) shall be accessible at all times & shall be mechanically protected against damage. (don't upset it in any way).

I hope this is not too confusing.

I'm not sure about all of this advice because back in the US when I replaced my main panel on my house I was required to have two earth electrodes seperated by a minimum distance (I think it was 6 feet) both electrodes being 6 feet long and driven so that only a small portion was left above ground (I can't remember exactly but about 6 inches exposed above ground). The two electrodes were connected to each other by an uninsulated cable of the same size that ran to them from the main panel....saying this another way is that there was a cable that came to the first electrode and was clamped to and then the cable went to the next electrode where it was connected also. The size of the cable connecting to the electodes was stipulated in the code and it was smaller than the size required to carry the total amperage that the main breaker could supply. The electrodes were steal and maybe thay had a copper coating but I can't remember. So......seems like there's more than one "safe and acceptable" method.

Edited February 23, 2006 by chownah

[elkangorito]

Hi Crossy & Chownah.

To Crossy.

Yes, I did train in Australia. 2 years as a radio technician (RAAF...didn't like it), 10 years as an "electrical fitter/mechanic" covering most facets, 14 years as a switchboard/control design engineer. I don't know everything because the rules are "living" documents...they change constantly. Crossy, see if you agree with what I am about to say, which is as follows;

The American system of electrical wiring is not "up to standard". The yanks have, for a long time, insisted upon using a 2 wire system. The "earth" connection (the third wire) came later. Generally speaking & from what I know from a "radio technician" mate of my'n in San Diego, the American system still relies upon the consumer connecting some of their consumer devices to earth "manually" (as he currently tells me). That is, the consumer still has to provide an earth from the metal clad appliance to the GPO earth. This is backward in thinking. Mind you, this may no longer be for every single case. I don't know if they use an MEN system.

As far as having 2 earth electrodes, this is fine as long as they (as you say Crossy) are both connected to the Main Earth Bar in the Main Distribution Board. Nothing wrong with having 2 or more main earths as long as they are positioned close together & correctly "mechanically/electrically bonded to the Main Earth Bar & then correctly connected to the Main Earth Bar in the Main Distribution Board.

Of course, proving the earth fault loop impedance is the only way to totally prove a good earth connection.

Conclusion.

To assume 'standards' from "home", is a mistake. I do not say that Australian Standards are the best but I do say that any standard that follows basic laws of physics, are very valuable. Also, most Australian Standards are derived from IEC/ISO standards & modified to suit temperature rise differences etc. After all, Thailand DOES use the MEN system. This means that American electrical standards do not apply.

Edited February 23, 2006 by elkangorito

[lopburi3]

The American system of electrical wiring is not "up to standard". The yanks have, for a long time, insisted upon using a 2 wire system. The "earth" connection (the third wire) came later.

While true the US has used a 2 wire system in the past I suspect most countries did the same. 50 years ago we used two wire but had a ground on every outlet box buy using the steel conduit/steel box/steel outlet frame/screw in outlet. When you wanted to ground an appliance or tool you attached it via a pigtail to the screw. Later third wire came in as there was less chance of poor or missing connection with direct wire. Don't have the timeline as have lived overseas since the 60's but I have always used ground wire (3 wire) in US electrical installations since the mid 60's so it is not something new to us.

I have never heard the name "MEN" but the US does use what is called a grounded neutral system which seems to be exactly what you are talking about. "The U.S. National Electric Code Article 250 requires that the ground wires be tied back to the electrical neutral at the service panel".

[Gary A]

So! If I connect all my earth rods together that will be the same as one earth? All I am after is to prevent getting shocked. Most Thai houses have no ground and shocks are common. I don't care about whose standards are better. NO SHOCKS! That is the goal.

[Crossy]

elkangorito

Being a Brit. I'm not conversant with the NEC (National Electrical Code), which is why I quote BS7671 and IEC 60364, both standards are widely accepted thoughout the world. But I believe you are correct in your assertions that it is 'not to code'

Meanwhile, do you have a link or document that actually DEFINES Thailands electrical standard? Thai language is OK.

If we can get hold of a decent local document we can build an 'idiots guide' that combines the best of the global standards and complies with whatever local regulations exist. I'm seriously considering producing such a document for ThaiVisa members and would greatly appreciate your input.

PM me if you want to talk privately, any and all input is appreciated.

So! If I connect all my earth rods together that will be the same as one earth? All I am after is to prevent getting shocked. Most Thai houses have no ground and shocks are common. I don't care about whose standards are better. NO SHOCKS! That is the goal.

The only absolutely safe way to do it is have a star-point where all your grounds and ground stakes connect.

The star-point is the earth bar in your breaker box.

[lopburi3]

So! If I connect all my earth rods together that will be the same as one earth? All I am after is to prevent getting shocked. Most Thai houses have no ground and shocks are common. I don't care about whose standards are better. NO SHOCKS! That is the goal.

Believe your first choice would be a ground wire from your electric system and use three pin plugs. If you do not have the 3 wire electric system then grounds tied together would be second and independent grounds third. By all means do have a ground; you know already there is leakage if you have received a jolt. What you have now in much, much better than nothing.

[Crossy]

So! If I connect all my earth rods together that will be the same as one earth? All I am after is to prevent getting shocked. Most Thai houses have no ground and shocks are common. I don't care about whose standards are better. NO SHOCKS! That is the goal.

Believe your first choice would be a ground wire from your electric system and use three pin plugs. If you do not have the 3 wire electric system then grounds tied together would be second and independent grounds third. By all means do have a ground; you know already there is leakage if you have received a jolt. What you have now in much, much better than nothing.

On the " 'owt is better than nowt" scale, definately agreed.

I have never heard the name "MEN" but the US does use what is called a grounded neutral system which seems to be exactly what you are talking about. "The U.S. National Electric Code Article 250 requires that the ground wires be tied back to the electrical neutral at the service panel".

Sounds pretty close to a MEN system to me.

Lop, what do you reckon to my idea of producing an idiots guide?

Edited February 23, 2006 by Crossy

[lopburi3]

I do believe it could be useful as there is always a great deal of interest when we discuss electrical matters. There are probably web sites, of a public nature, who would be willing to allow reproductions of drawings and such if asked. Would be very interested in seeing an official electric code or policy for Thailand.

[chownah]

Present wiring code in the US requires a hot wire, neutral wire, and a ground wire to everything for newly constructed circuits....old circuits do not have to be upgraded if not replaced. New outlets are three prong with the addition that the two current carrying conductors (hot and neutral) are connected with correct polarity to the outlet which has two slightly different sized slots so that when an appliance which has no ground (a two prong plug) will only fit in one way and this maintains polarity. I have never had to establish my own ground wire conncection with any appliance....any appliance that requires a ground connection will already have a three prong plug with all three prong wired properly already at purchase.

[elkangorito]

Gents,

All this talk about different standards & codes will become confusing. Let's be clear here. It is a FACT that the Thai Electrical system uses the MEN system. I know this from an Australian who has an electrical engineering business in Pattaya (11 years)...mind you, he is in constant "awe" of the lack of understanding that Thai electrical personnel have for this system.

Secondly, most Australian standards (I do believe Thai standards as well), come from European Standards ie IEC/ISO Standards, although I'm yet to find "DEFINITIVE" Thai standards. Consequently, there is no room for error. These standards are based upon the laws of Physics, not the laws of a country.

Those who wish to believe that multiple earth stakes are "better than nothing", can, in actual fact, be creating a problem for themselves. Electricity does not follow the laws of humans. To the contrary, humans follow the laws of electricity. Please, at least have one earth stake but multiple earth stakes MUST be placed in close prximity to each other (within 3 metric metres).

I will not not reiterate one of my previous posts, in which I outlined the earthing requirements & MEN requirements for a "safe" installation. Those who wish to ignore "physics" will be taking a risk...or 3.

There are legitimate reasons for these things & if one does not understand mathematics, physics or chemistry & still chooses to believe in "out dated" information, then SO BE IT.

With regard to the yank earthing system, it is "below the standard". For example, Australia has been a 3 wire MEN system for at least 30 years...possibly longer. My current American friends constantly tell me how much trouble they have with electrical "safety". The only reason is that they are "electrical" people & know what is NOT going on.

At the end of the day, there is NO easy way out or nor is there an alternative. An MEN system will be your PRIMARY defense against electrical shock. This MUST be done according to the RULES (based upon laws of physics). If you wish to do otherwise, you will be taking a BIG electrical risk.

Edited February 24, 2006 by elkangorito

[Crossy]

elkangorito, et al.

Been talking to our sub-station design chap who has a copy of the MEA and PEA regulations.

MEA (metropolitan electric authority) defines (as you rightly say) ONLY the MEN system, MEA provide multiple earth points along the neutral and they encourage the use of individual earth stakes as well. A VERY SAFE SYSTEM !!!!

PEA (provincial electric authority) also use a MEN system BUT allows TT in remote areas.

If you are in the sticks you need to find out if your local area is wired as MEN, which probably means talking to a good electrical contractor. Chances are, if you're on the end of 2km of damp string you'll be wired TT and an MEN link should not be installed.

Unfortunately, the MEA/PEA regs don't say anything about the wiring inside the building, they are concerned only with the wiring as far as your main breaker (your side of the meter).

Edited March 1, 2006 by Crossy

[elkangorito]

Hi crossy,

I agree with you 98%...except about the number of earths. I will only agree upon multiple residential earths providing that they are not placed further than 3 metres apart from each other. This will nullify the chances of "earth potentials" & also maintain an installations low earth resistance.

Cheers, Rob.

[elkangorito]

elkangorito, et al.

Been talking to our sub-station design chap who has a copy of the MEA and PEA regulations.

MEA (metropolitan electric authority) defines (as you rightly say) ONLY the MEN system, MEA provide multiple earth points along the neutral and they encourage the use of individual earth stakes as well. A VERY SAFE SYSTEM !!!!

PEA (provincial electric authority) also use a MEN system BUT allows TT in remote areas.

If you are in the sticks you need to find out if your local area is wired as MEN, which probably means talking to a good electrical contractor. Chances are, if you're on the end of 2km of damp string you'll be wired TT and an MEN link should not be installed.

Unfortunately, the MEA/PEA regs don't say anything about the wiring inside the building, they are concerned only with the wiring as far as your main breaker (your side of the meter).

Crossy,

What is TT? Is it similar to the SWER (Single Wire Earth Return) system? If it is, this system is normally at about 19kV+ in Australia & generally, the earths of a HV system are not electrically associated with that of an LV system. Of course, there are allowances in this case.

Cheers,

Rob.

[Crossy]

What is TT? Is it similar to the SWER (Single Wire Earth Return) system? If it is, this system is normally at about 19kV+ in Australia & generally, the earths of a HV system are not electrically associated with that of an LV system. Of course, there are allowances in this case.

Cheers,

Rob.

Rob.

TT is neutral grounded only at the transformer, ground stake in the house NO MEN link, requires a good RCCB / ELCB / RCD to be really safe. Not the best, but it's what they do

Piccy attached.

Dave.