Memory Upgrade Problem

[Harry2]

I bit the bullet today after 3 years with 512 MB memory & got a 512MB module to fit into my third memory slot - now my system shows I have 768MB. Previously I had two 256MB modules (PC 2100) showing 512MB.

I have tried the Crucial System Scan from the web & it shows I have 768MB plus one free slot. I have tried putting the memory into different slots but it never goes to the 1024MB I was expecting.

All the modules are PC2100 but I noticed one of the original 256MB modules was single sided whilst the other two were double sided. Anybody any ideas on how to get all 3 modules ‘firing’ at once. Thanks.

PS I am using Windows XP.

[lopburi3]

Memory is fickle, especially when you start using different modules but my first check would be the mother board specs to make sure it can handle 512 in a slot or not. Even if this is the case you did get another 256 so all is not lost. But from your scan report it would seem it may see your 512 and one 256 ok and not see the other. Try taking one 256 and then the other out and see if there is any difference from the 768 report. If so you can determine the bank that is not working. I doubt that there is anything you can do to get it to play if system allows but it just not working together.

[Firefoxx]

Some mainboards aren't able to address many different "banks" of memory. In your case, the 256MB modules each take up 1 bank, and the 512MB is probably taking up 2 banks. The mainboard is probably only seeing 1 of the two banks on the 512MB module. If the mainbord's limit is only 3 banks, then you've got no solution. Usually the manual will state something about how you can populate the different slots.

You could try moving the 512MB module to another slot. I don't think it will solve the problem, but it's worth a try.

[Harry2]

Thanks Lopburi3 & Firefoxx for your suggestions. Perhaps predictably, switching the memory around did not send up getting me my 1024MB & I guess for one reason or another only 2 banks out of 3 'work' in practice.

[sbk]

This is interesting as I am planning on adding memory too (ancient machine, very slow). Which currently has one 256mb module, pc2700.

I know I need to get another pc2700 but are you saying its better to get another 256 module then or would it be ok to add a 512?

[francois]

hi'

alright, no absolute in ram, but one thing for sure single sided and double sided don't go together well, sometime don't even boot

try to put this 512 alone and see.

then try again, if fails, change for the same brand and size that the previous one, if can't, change for a 2x512

francois

Edited April 9, 2006 by francois

[elkangorito]

Memory is fickle, especially when you start using different modules but my first check would be the mother board specs to make sure it can handle 512 in a slot or not. Even if this is the case you did get another 256 so all is not lost. But from your scan report it would seem it may see your 512 and one 256 ok and not see the other. Try taking one 256 and then the other out and see if there is any difference from the 768 report. If so you can determine the bank that is not working. I doubt that there is anything you can do to get it to play if system allows but it just not working together.

I agree fully with Lop.

Also, were you sold the wrong memory? Maybe they sold you a 256 instead of a 512? Test it as Lop suggests.

RAM is voltage sensitive so make sure you check the motherboard requirements before plugging in just any old RAM.

By the way, why are you only upgrading to 512 of RAM? Maybe if your motherboard is old (2 years or more), it's time to upgrade it as well. These days, RAM is cheap & most current Microsoft OS's will work faster with at least 1024 Mbytes of RAM. Personally, I use 2048 Mbytes of RAM & I force Windows XP Professional to use RAM instead of a 'pagefile' (I do not utilise a 'pagefile' on my system). It has made a significant difference with speed on my computer.

Just another thought, check your 'Front Side Bus' (FSB) speed. It's of no use getting RAM that is faster than the FSB speed of your motherboard.

One more thing...use 'certified' RAM. There are not many brands but I would suggest using Kingston RAM, which is certified. Certified RAM is far less likely to fail (it is more expensive) than other cheaper uncertified RAM.

Edited April 9, 2006 by elkangorito

[Harry2]

Thanks Francois my hunch is this is a single/double sided memory issue.

hi'

alright, no absolute in ram, but one thing for sure single sided and double sided don't go together well, sometime don't even boot

try to put this 512 alone and see.

then try again, if fails, change for the same brand and size that the previous one, if can't, change for a 2x512

francois

[John_Betong]

Hi All,

I have a desktop system which was supplied with 512 megs of memory (in one of my two memory slots). I decided to buy another 512 megs. Here is the saga of trying to get it to work.

First Panthip trip:

The purchased memory was tested in the shop and worked fine.

Got home and it did not work.

Second Panthip trip:

The supplied memory was tested once again and worked fine so an additional cost of about 150 baht was charged to replace the memory with a better type.

Got home and it did not work.

Third Panthip trip:

I took my computer to Panthip, tried numerous types of memory, eventually found some that was compatible. Charged again about 200 baht.

Got home and fortunately both memory banks worked fine.

Cheers,

John_Betong

[elkangorito]

Hi All,

I have a desktop system which was supplied with 512 megs of memory (in one of my two memory slots). I decided to buy another 512 megs. Here is the saga of trying to get it to work.

First Panthip trip:

The purchased memory was tested in the shop and worked fine.

Got home and it did not work.

Second Panthip trip:

The supplied memory was tested once again and worked fine so an additional cost of about 150 baht was charged to replace the memory with a better type.

Got home and it did not work.

Third Panthip trip:

I took my computer to Panthip, tried numerous types of memory, eventually found some that was compatible. Charged again about 200 baht.

Got home and fortunately both memory banks worked fine.

Cheers,

John_Betong

Did the people at Pantip install the RAM into your computer, test it & then remove it? If so and subsequently, did you re-install the RAM into your computer when you arrived home? If this happened, then it could be likely that 'static electricity' killed the RAM, as YOU installed the RAM into your computer.

Was the RAM 'Dual Channel' RAM?

Does your motherboard support 'Dual Channel' RAM?

How did the people at Pantip 'test' the RAM?

Do you have any electrical problems at your house?

Edited April 11, 2006 by elkangorito

[John_Betong]

Hi All,

I have a desktop system which was supplied with 512 megs of memory (in one of my two memory slots). I decided to buy another 512 megs. Here is the saga of trying to get it to work.

First Panthip trip:

The purchased memory was tested in the shop and worked fine.

Got home and it did not work.

Second Panthip trip:

The supplied memory was tested once again and worked fine so an additional cost of about 150 baht was charged to replace the memory with a better type.

Got home and it did not work.

Third Panthip trip:

I took my computer to Panthip, tried numerous types of memory, eventually found some that was compatible. Charged again about 200 baht.

Got home and fortunately both memory banks worked fine.

Cheers,

John_Betong

Did the people at Pantip install the RAM into your computer, test it & then remove it? If so and subsequently, did you re-install the RAM into your computer when you arrived home? If this happened, then it could be likely that 'static electricity' killed the RAM, as YOU installed the RAM into your computer.

Was the RAM 'Dual Channel' RAM?

Does your motherboard support 'Dual Channel' RAM?

How did the people at Pantip 'test' the RAM?

Do you have any electrical problems at your house?

In answer to your queries:

When I mentioned 'test' the memory was plugged into one of their computers and it worked fine as mentioned in my First trip.

If as you mentioned that when the memory was removed from their computer or when I installed it into my computer, 'static electricity' killed the ram. This is indeed a possibility and also that on the return journey on my second trip the killed memory was resurrected probably from the Skytrain's static electric. Once again it worked fine on arrival when they plugged it into their computer to determine that their returned memory was not the problem.

I have no idea about what type of memory was involved, the point I was trying to make is that the only "acid test" it to get identical ram and hope it works. They could not supply identical ram as far as manufacture and specification was concerned so they gave me an alternative which worked when my original memory and their memory was plugged into their computer (my first trip).

As far as electical problems in my house are concerned then the computer does give me a slight shock.

After my third trip to Panthip and I returned home with my computer, the memory worked and I still have the case is still slightly live.

Today is a "replace and test society", it is so much easier to do this when there are numerous other items which can be tested in another computer.

Chokdee,

John_Betong

[stumonster]

After my third trip to Panthip and I returned home with my computer,

the best method if you are not totally sure about the memory type you require is to take your box and manual with you to the shop.

[meadish_sweetball]

My advice is to keep the RAM packaging and bring that to the shop when it is time for an upgrade.

[elkangorito]

As far as electical problems in my house are concerned then the computer does give me a slight shock.

John, this could be the cause of many of your problems. It sounds like (& I will bet my left nut) your residence is not properly earthed...nor does it have an MEN link. Without these 2 things, many of your appliances will suffer shortened lives. Not only this but your whole household is at a GREAT risk of electrocution.

It is not normal in Thailand, although it is the 'rule', to properly earth an installation & ensure that an MEN link is utilised. Many Thai electricians do not know this fact & will state, 'this is Thailand'! They will even refute this. If they don't know what an MEN link is or don't know about proper earthing, see the below advice about Breaker Box Wiring below.

Without a 'proper earth' & an MEN link, you will have a voltage on the Neutral conductor. This conductor should NEVER have a voltage upon it (with respect to earth). This is a typical Thailand problem, which is responsible for many deaths as well as premature equipment failure.

For more info, search for the "Breaker Box Wiring" post.

If you adjust your electrical installation as prescribed by information in the Breaker Box Wiring posts, you will undoubtedly see a markedly reduced failure of electrical equipment & also a far greater safety level within your household.

Edited April 13, 2006 by elkangorito

[sting01]

[quote This conductor should NEVER have a voltage upon it (with respect to earth). This is a typical Thailand problem, which is responsible for many deaths as well as premature equipment failure.

Well, simply saying you are rite, but technically speaking you are wrong.

First neutral can have a voltage, neutral is only the medium point btw the 3 phases, so neutral will have a voltage. But neutral should NOT have a potential difference with the ground, or yes you will get electrical shock. To precise , the tranfos in thailand create neutral from the phases, and not from the ground as we can mostly have in europe.To precise also, ground here stand for both the yellow/green cable (electrical ground), and the place where you feet are.By respect for the international norma, the general ground must be also relied to the existing objects in metal in an appartment or an house (like the plumbery), to make all at the same potential. The metal bar inside the concrete also have to be connected to it. There is no easy solution, assuming that is never made here.

There is another problem, mostly forget by ingeneer. That is the harmonic current. LEt say it's usual when you install electric cable to use a cable half size for the neutral, because the nature of the tri phazed electrical ... But if you take a building full of IT eauipments, you have to use the same size for both neutral and phases.

Death are not caused by that, but caused by a long latency before the 'disjoncteur' cut. The way to go is simply to instal a 30 ma (the cost was 30 fr 5 years ago for Merlin gerin. It's a cheap part.

Ground is a real issue in thailand, so any thing that can improve it is well comed.

[elkangorito]

[quote This conductor should NEVER have a voltage upon it (with respect to earth). This is a typical Thailand problem, which is responsible for many deaths as well as premature equipment failure.

Well, simply saying you are rite, but technically speaking you are wrong.

First neutral can have a voltage, neutral is only the medium point btw the 3 phases, so neutral will have a voltage. But neutral should NOT have a potential difference with the ground, or yes you will get electrical shock. To precise , the tranfos in thailand create neutral from the phases, and not from the ground as we can mostly have in europe.To precise also, ground here stand for both the yellow/green cable (electrical ground), and the place where you feet are.By respect for the international norma, the general ground must be also relied to the existing objects in metal in an appartment or an house (like the plumbery), to make all at the same potential. The metal bar inside the concrete also have to be connected to it. There is no easy solution, assuming that is never made here.

There is another problem, mostly forget by ingeneer. That is the harmonic current. LEt say it's usual when you install electric cable to use a cable half size for the neutral, because the nature of the tri phazed electrical ... But if you take a building full of IT eauipments, you have to use the same size for both neutral and phases.

Death are not caused by that, but caused by a long latency before the 'disjoncteur' cut. The way to go is simply to instal a 30 ma (the cost was 30 fr 5 years ago for Merlin gerin. It's a cheap part.

Ground is a real issue in thailand, so any thing that can improve it is well comed.

Dear Sting,

Do you know what an MEN link is? Do you know about power reticulation in a 'distribution" system? Do you understand anything about earthing? Neutrals MUST NOT have a floating voltage upon them. Such things cause MAJOR problems. If you disagree, you will be arguing against 99.9% of electrical engineers from all over the world.

I strongly suggest that before you post such DANGEROUS advice, consult an electrical engineer. What you are saying is incorrect & dangerous, & THERE IS an easy solution. It's called an MEN link & a proper earth connection.

As for harmonics (my favourite subject), such things are generally NOT a problem in a residential installation (which is what is being discussed here) unless major industries have been set up in the neighbourhood & off the same distribution transformer. Normally, residential installations do not need to worry about harmonics because they are isolated by a 'residential' distribution transformer that is appropriately earthed at the 'star point'.

Edited April 13, 2006 by elkangorito

[sting01]

If you read what I typed (in bad english I agree) you will see I spoked about buildings loaded with computers. Obviously that is not a condo case (I do agree). May I give the IBM tower in Sophia Antipolis (France) as exemple (the only time I got this problem during my professional life).

For the rest, what I am saying is not dangerous, the fact to insert a 30 ma disjoncteur (not sure about the english name, but any specialist get it right when they see 30 mA), it's not DANGEROUS but improve the seciurity , mostly in wet places, because that shut down the electricity before any corporal damage (or brain damages, or nervous damages).

Anyway, as it's a requirement in EU (at least, not sure in skippy -very famous kangaroo- land how is it), I always did and continue to do when spoken about electrical voltage >12 V, use the BIble, mean the book called NF C 1500, the lectrical norm and the way to do, the book is in french but is the carbon copy of the International Norme (just translated, because it was obvious us french we are not clevert enought to read fluently english). So if any of what I said is wrong, please send your very interresting thought directly to the international office who make the normes. I am sure you will enjoy the undreds of thousand electric specialist all around the world. As security was your concern, and as the fact to insert a 30 mA (called disloncteur differentiel in french, should differential disjoncter I suppose in english, differential because it shutt off the power when thepotential got different btw neutral and ground) is dangerous, and as it's the way to do in EU, you will save thousand of life, save also millions of euros to the insurance companies (they will not pay for that), and maybe get Earl of something, Marquess of something, or get some awards from the Empire (forget the name, the same as Elton John or the Beattles).

About my qualifications, I am just n2p3, with a background in construction (condo and offices, not house, because for electricity in france that is a different path) and in fabric (you know what I mean certainly, press, extrusion press) for SPIE (7 years) and INtexalu(3years). I was awarded a master of electrotechnic in 1995. Also, I do not work in this fields since 2000, so I easily admit technology went forward in 6 years, but not on that topic , parts are certainly better, but why we use that part at that point have not change, nor how electricity nature have changed, nor the equations who have lead to the norme adoption.

So sorry , what I said, and also notice I was simply corrected your wording, because as I stated, for the normal person, the way you explained is enought to know (he will not cares about theory).

I can re do it agains. When you use a Metrix (sorry that is a brand, but easy to get what I am saying), and mesure the V, you in fact measure the diffence btw 2 poles (usually that is phase and neutral). In a normally protected installation, if you measure the V btw ground and neutral it must be 0, but it does not mean there is no electrical current inside the neutral, obviously it must be if any electrical appliance is working.

Have fun mate

[elkangorito]

If you read what I typed (in bad english I agree) you will see I spoked about buildings loaded with computers. Obviously that is not a condo case (I do agree). May I give the IBM tower in Sophia Antipolis (France) as exemple (the only time I got this problem during my professional life).

For the rest, what I am saying is not dangerous, the fact to insert a 30 ma disjoncteur (not sure about the english name, but any specialist get it right when they see 30 mA), it's not DANGEROUS but improve the seciurity , mostly in wet places, because that shut down the electricity before any corporal damage (or brain damages, or nervous damages).

Anyway, as it's a requirement in EU (at least, not sure in skippy -very famous kangaroo- land how is it), I always did and continue to do when spoken about electrical voltage >12 V, use the BIble, mean the book called NF C 1500, the lectrical norm and the way to do, the book is in french but is the carbon copy of the International Norme (just translated, because it was obvious us french we are not clevert enought to read fluently english). So if any of what I said is wrong, please send your very interresting thought directly to the international office who make the normes. I am sure you will enjoy the undreds of thousand electric specialist all around the world. As security was your concern, and as the fact to insert a 30 mA (called disloncteur differentiel in french, should differential disjoncter I suppose in english, differential because it shutt off the power when thepotential got different btw neutral and ground) is dangerous, and as it's the way to do in EU, you will save thousand of life, save also millions of euros to the insurance companies (they will not pay for that), and maybe get Earl of something, Marquess of something, or get some awards from the Empire (forget the name, the same as Elton John or the Beattles).

About my qualifications, I am just n2p3, with a background in construction (condo and offices, not house, because for electricity in france that is a different path) and in fabric (you know what I mean certainly, press, extrusion press) for SPIE (7 years) and INtexalu(3years). I was awarded a master of electrotechnic in 1995. Also, I do not work in this fields since 2000, so I easily admit technology went forward in 6 years, but not on that topic , parts are certainly better, but why we use that part at that point have not change, nor how electricity nature have changed, nor the equations who have lead to the norme adoption.

So sorry , what I said, and also notice I was simply corrected your wording, because as I stated, for the normal person, the way you explained is enought to know (he will not cares about theory).

I can re do it agains. When you use a Metrix (sorry that is a brand, but easy to get what I am saying), and mesure the V, you in fact measure the diffence btw 2 poles (usually that is phase and neutral). In a normally protected installation, if you measure the V btw ground and neutral it must be 0, but it does not mean there is no electrical current inside the neutral, obviously it must be if any electrical appliance is working.

Have fun mate

You may like to search for & read the "Breaker Box Wiring" posts, where these points are discussed at length & in reasonable depth.

[sting01]

When I speak about technical subjects, or when I do technical works, I always do it with the related official documentation.

In this particulary case I refer to the NF C 1500, as stated precedently. If as I suppose, in australia you also have reference book, corresponding to the international norme, please refer to it. I will certainly not to something that was said somewhere by someone.

So please, if you have concrete, technical, and internationaly (eventually only localy mean australian) accepted documentations that say installing a 30 mA is dangerous, or made all the mettalic part of a condo with the same potential is dangerous, please please, I beg you (and with me hundreds of thousands electrical enginers with millions of electrical technicans or handymen) to give us the link, the book, the editor, the author.

For me it's simple, it's Association Francaise des Normes, it's a governemental association who translate and publy the international normes. More in my country, as everywhere in europe, it's consider 'state of art' to follow that norme, and if you are a proffessional the fact to not do so is a wrong doing and lead to jail (because you do not respect the safety of your clients).

If the fact I named a firm for the product is what make you 'sarcastic', I trully did not remenber the other society who sold it. Anyway speaking of Merlin Gerin for electrical part is like speaking about Microsoft or Sun in a conversation related to IT topic , very common.

On the other hand I do pretend to know all, and as I am only an humble n2p3, and as I did worked in electricity field since 5 years, I can be outdated. So give reference, serious one, that invalidate why I said. Serious mean documentation or recommendation by austalian union of electricity companies, or australian university of technology (assuming you are australian and electrical engineer, because I am fully indoubt you are electrical engineer. Mostly engineer are hyper competent, and will immediatly comment with the right formula if I have say something inexact).

Anyway, in another topic you stated you knew better about IT science than any IT professional (I am a member or IETF, what about you?). Here you also give shadow explanation , and claim I am saying inexact and dangerous affirmation, are you also an electrician (as stated I am n2p3), or are you an engineer in electricity (one of my 3 masters is electrotechnics, got in 1995, what about you?). Can you give accurate documentations, widely accepted as the 'state of art' proposals by the professionals of that field, as the international norme is (NF C 1500, where is your documentation).

Be aware technic is not only blahblah, be also aware electricity can be dangerous. Be aware some knowledges do not come like that morning because you did a dream, but it take years in schools or university to aquire and more years to do it where you learn also more.

To make brief, you state neutral must not have V (I do not know if in english it's Volt or Voltage, so V is okie). I stand firm neutral have V, but you will not get electrical shock if you do not have difference of potential btw neutral and the place where your feet belongs.

If not, how the people will be able to work on the aerial lines that have 20 K V? Do you think they turn the power off before? Shuttdown the dam, or the nuke plant? LOL. They are simply at the same potential, because they do not touch the ground. It's not also because the protection, 20 K V with a huge A is not stopped by the protection, take a neon light and go under one of thoe line and you willsee, the neon light with work.

You speak using very well formated language, thing that I can not do, my english is broken, but your words are empty, have no meanings, and can mislead people. Think before to post.

[elkangorito]

Hi Sting. Thanks for your post. It is obvious that we share a communication problem, so I will try to keep my English as simple as possible.

In your post, my major concern was about the Neutral conductor having a voltage (V). This voltage can be measured between active & neutral. For example, if the system is a single phase 220 volt system & there is 180 volts between the active & the neutral, this means that the neutral conductor has about a 40 volt potential. Of course, this can only be assumed if the voltage between active & earth is 220 volts.

This is a matter of Physics & safety...not rules. An M.E.N. (multiple earthed neutral) link is an electrical link at the Main Distibution Board, between the Main Earth & the Main Neutral. This link effectively prevents any floating voltage (V) on the Neutral. This is the only reliable method of preventing the neutral from having a voltage on it (compared to earth). There is no other way. Also, at the 'star point' of the distribution transformer, the 'star point' must be earthed. I assume you know about 'star connected' 3 phase systems.

You mentioned RCD's, which are known in Australia as Residual Current Devices. These devices are usually mechanically connectly with a circuit breaker, which changes their name to an ELCB or Earth Leakage Circuit Breaker. The trip current & time is 30 mA @ 20 mS for a domestic installation. The only problem with these devices is that they are electronic & can fail at any time. This is why Australia & some other countries use the M.E.N. system of earthing. The M.E.N. system is considered the Primary Defense against electrocution while the ELCB (RCD) is considered a Secondary Defense, because an ELCB/RCD is not as reliable as 'hard wiring'. The reason why other countries do not employ the M.E.N. system is most likely due to the cost of changing over to such a system. By the way, it is possible to be electrocuted even if you use an RCD/ELCB. If, somehow, you become connected across the active & neutral, the RCD/ELCB will not trip & you may die.

The other advantage of using an M.E.N. system is that it eliminates a dangerous floating voltage on the neutral (as discussed earlier). Not only is this floating voltage dangerous, it usually has bad effects on sensitive equipment like computers, TV's etc. Generally, this floating voltage reduces the life of the equipment. An M.E.N. link will also help to reduce harmonics in a system.

The 'physics' of this discussion are not evident within the NZ/AS 3000:2000 (Australian Wiring Rules) but these rules are based upon physics.

By the way, I did not think that any of your posts were sarcastic. I responded with a 'concerned' tone.

I say again, any voltage present on the neutral (measured to earth) is not only dangerous but will certainly have bad effects on sensitive equipment.

As far as my comments in the 'IT' post are concerned, the point I was trying to get across was simple...there are ultimately no shortcuts with computers. If somebody doesn't want to learn about computers or is unable to learn about computers, then that person will sooner or later be in trouble.

Many people are advised by 'experts' to add software to solve problems. These problems could otherwise easily be solved by a simple understanding of 'File Management' & not by adding software. All it takes is a little time & energy that can save a lot of time, energy & money. If none of this was evident in my posts, then I have failed to communicate correctly. As you know, the more software you have on a system, the more problems you are likely to have with that system. I did not say that you provided 'inexact and dangerous affirmation' in that forum.

I will PM you about my qualifications.

[stumonster]

a small diagram of the MEN wiring system for single phase installations.

http://www.novaris.com.au/images/stories/S...ng%20System.pdf

[sting01]

It's obviously a communication problem, it appear when reading your last post.

Obviously, I lack the correct naming in english.

So I am thinking we were simply saying the same, or similar, but I blocked on your naming that were not those I knew (or supposed knew).

Well, about the 30 mA, they happily not fail easily, The MEM is not used in France (not so often in my knowledge) because the neutral is created from the ground at the main transformateur level (sub station for exemple, at least the place where electricity is transformed for both V and A to something that can be used for both individual and fabric usages, namely a good old 380 V and 100 A). that is the opposite of what I constated in thailand. Here neutral is created at the neutral point of the 3 phases. I do suppose you know both technology exist and have the same result but with different problem.

That difference explain :

1) why you advertise for MEM.

2) why I was advertising to make all possible ground with the same potential.

For both, but depending of the technology used at the sub station, the result is the same. Neutral must have a potential equal to ground.

Obviously also, I had to (silly me I did not) more explain why I was spoken of that, and give the precise case (I think I did, but certainly not correctly). It also explain why I spoked about armonics, because they are more problematic in the case of a neutral from ground, than in the technology used in NZ. On the other hand, I think the neutral from ground is offer other advantages (in fabric, you can easily recreate a new ground circuit from a neutral for the command system in case of difference of potential).

So at least a good news, we knew both of us what we were talking

Cheers

[sting01]

a small diagram of the MEN wiring system for single phase installations.

http://www.novaris.com.au/images/stories/S...ng%20System.pdf

Got it, but as stated many times, there is 2 technologies to create the neutral, and in France I used only the neutral from ground, So what the MEM do is already done before to arrive for usage, and a system like that could be potentially dangerous (because it would create a difference of potential btw the neutral, the old ground, and that one). Let say in france we have an installation similar to the distribution #3 (not really but I will pastthe technical details).

that is why it's so important to make each and every metalic part in a construction connected to the electrical ground (in France I mean).

So , yes I have learn something (I was not familiar with the MEM), and it have make me remenbered things.

Last point, it also explain why I claimed a potential in the neutral is normal, because we always consider Neutral to have the same potential as ground so, if any difference (appart the armonic case), it will never last long enought to be measured (the sub station will turn of immedialy for safety purpose, then restart automatically by 3 times after 1 mn, then 3 mn, then 10 mn if the problem is still here then the engineers will come to check.)