Grounding Systems for CPI

Why don't you start by discounting the ones that are illegal based on the regulations, electrical standards and codes of practice for the site in question.

which of them do you consider are ilegal, so I can understand, please. be more explicit.

Electrical standards and regulations vary from country to country and even from site to site (we have American sites in New Zealand operating a combination of New Zealand and American electrical standards and regulations for example).

The point is it is site and country specific (and in special cases equipment specific within the standards, double insulated equipment is NOT earthed for example), so what may be acceptable on a site designed to American earthing standards may be illegal when compared to European or New Zealand standards.

The electrical standards dictate what type (or lack) of earthing must be used for equipment and personal safety, regardless of any advantages other systems may offer.

What site electrical standards are you working to and what do they say? I am in no position to offer real world application advice if the site is to Indian, Saudi or American standards.

Others may but you need to advise us what country and standards the site is in.

Really Sir, it is the second time you say to me that this forum is not the place to get an education. I recognize your are a wise person but this expression is not a kind style for this place. I'm not a disigner trying to get an easy technical information, I just intent to know different opinion about any issue like everyone in this forum.

Yes I know the standard an regulations applicable for any of the four mentioned grounding system. Why my question??, Just because I have seen either "low resistance grounding and ungrounding system used indiscriminately in MV distribution system, both within standard and regulations no matter place or contry. What I just pretend is only to exchange critera and experiences about it, like all participant do in this wonderfull forum.

Bye

Bare with us as we have been getting an increasing number of posts by people appearing to be doing dangerous, illegal things they are not qualified to do. After answering a pile of these it is understandable that some of us who work in the associated industry's start to get a little tetchy when answering similar-appearing questions.

If this is for general interest (and not a homework question) that is a little different, but please indicate in future if your question is for general interest only so we know you are not some unqualified person asking us to help you do something incredibly dangerous and illegal like designing a real site's electrical protection.

As Engineering professionals we have a legal and ethical responsibility to prevent this sort of thing when we see it (varying depending on the situation of course). We can only guess based on the information given in peoples posts, and obviously we aren't perfect at guessing the posters true intent.

_{Jack - Watched someone almost die an hour ago.....so, safety everyone!}

I respectfully acept your coment, I promise to specify in future any comment be make for general interest, zorry for any inconvenient cause by me to your reputation that I consider haigh as well as the rest of the furum member.

If you have any technical comments about my question grounding to be choice, will be very appreciated

By

British Standard 7671 <yawn>.