How to provide earthing in Jetty

Re: earthing resistance at jetty

By following your local codes. Obviously you don't know your local codes. This leaves you with just a few options.

1. Take a certifying class
2. Look up your local building and wiring codes
3. Hire a qualified electrician

Now others may make suggestions here on your question,

"How to provide earthing in Jetty ??"

But you provide for us no description of where is this Jetty, what is this Jetty made of or even how the power gets to your Jetty. From your tiny description the only suitable answer should be "Use wire." Without knowing any site specific considerations, any suggestion will only be a guess. To properly install a grounding system anywhere on anything requires knowledge of where this ground system will be and what will be grounded. The grounding of a radar installation next to the Bearing Sea will be very different from the grounding of some pier light poles in Baja California. Heaven forbid your installation one day electrocutes somebody and you claim a good ground installation solely from what you learn here.

It is covered in British Standard 7671. In fact, most things electrical are covered in British Standard 7671.

There's a question related to this topic that I couldn't find an answer to in BS7671:

Are there standard practices/guidelines for jetty earthing intervals? The jetty under consideration has 60m long concrete piles every 12m or so. Each pile has an exposed steel joint at 30m and 60m marks, and both joints are within the seabed (water under jetty is 13m deep).

There's contractual earthing resistance spec of 5 ohms or less with one disconnection of the jetty's earthing ring connecting earthed piles, and based on prelim measurements/calcs/estimates, each pile should achieve this. But am trying to check whether:

1) there are any standards requiring jetties directly earthed every 20m (similar to building earthing intervals), or whether

2) it's acceptable practice for jetties directly earthed at longer intervals, e.g. every 36-40m (similar to large offshore platform jacket leg distances)

Thanks for your feedback on this.

Adam

Go back to the contract, and ask there.