Conductor Size Required for Transformer, Generator for Frame Earthing

According to the codes and standards in effect where this is being installed. With the complete lack of information in your post, no other answer is possible.

Thanks for your response. Please consider it for BS/IEC/NFPA.

Impossible to answer, except to say, the correct one per local and national codes.

Do a search; here's one:

IS SP 30: National Electrical Code : Bureau of Indian ...

It is about this big.

If you really don't wish to duplicate this type of wiring then you should understand your circuitry a little better than what you've told us and consult with the wiring authority for this installation.

British Standard 7671 gives full protocols for cable sizing, as has been repeated in this forum on countless previous occasions.

Reported as a possible duplicate thread.

What is the fault current at the transformer, generator?

Thanks for your response.Please consider 1000 KVA, 11/.415 KV ,Dyn 11 Distribution transformer.

In all the power plants I have been for the last 40 years, the wire size is a minimum of 1/2 inch. I do not know what the actual wire size is. There are so many different grounds in a plant that it seems to be a standard size due to the fact that it is not load bearing. Check local codes to get the correct size.

Do not confuse Grounding with Grounded, a common mistake.

The largest conductor going to the electrode,in the ground,is #6 Copper.

There are exceptions ,of course, to every rule, and this rule is no exception.

Per NEC,article 250.

Read and understand this section thoroughly before proceeding.(CYA)

I did not get confused. He is grounding the FRAME and not grounding the load.

My reply was directed to the OP,not you.

Thanks for your response and cooperation. I need conductor size from frame to the electrode. Could you please provide me the clause no from Artical 250 of NFPA that I can check. Actually I am confused about the issue and want to make my conception clear.

If you're going to check on the answers given, why not look for the conductor size yourself.

You could give the size of the conductor that you've calculated and we'll tell you if you're right.

In other words "do your own work."

As I stated,it is important that you read and understand the Article 250.

To give you a portion out of context would be dangerous.

You must understand the theory as well as the process to safely perfom electrical installations.

If you do not understand it on first pass,do some further research or experience to enlighten yourself.

The code book is not designed to be a cookbook,with recipes on "how-to-do", it is merely stating what must be done to achieve a safe installation.

There are so many variations on installations that a strong undestanding of priciples is required.

This is why many years of experience is required before a hopeful electrician can even apply for a license.

Memorizing the entire code book will not get you there.

This is not an exclusive club, to exclude others, rather all who are qualified are welcome.

General advice is all I can give you for the safety of all concerned.

Please inform me your mail ID thro this forum's mail box so that I can send you a chart on the same.

See also: British Standard BS 7430 Code of practice for Earthing

Ch.18-19 [mainly 19.7.2 Size.

IEEE-Std 665-1995 IEEE Guide for Generating Station Grounding

ch. 5.3 Generator and isolated phase bus grounding

Thanks for your response and guidence.