More than a little disappointed I haven't had any meaningful reply yet.
Really I should be demanding my money back as this guide isn't worth the paper it's printed on.

Dear Graham

The IET technical helpline is for enquiries relating to BS 7671. For enquiries relating to IET codes and Guidance publications and activities, the email address is ietstandardsenquiries@theiet.org.

I have searched the IET technical mailbox but unfortunately I am unable to locate your enquiry. Are you able to resend it or provide the date it was submitted please?

Many thanks

Michael

This seems like advice from an older version. I read some main requirements from BS 7671 : 2008+A3 : 2015. They say that metalwork in boats cannot be supplied from a PME supply and only TN-S can supply houseboats and pleasure craft. TN-C-S is allowed for marina buildings (like offices, homes, stores etc). Because many marinas are large and varied, installing a TN-S system may be feasible. This makes sense if the marina has its own transformer.

Can't be. This is the first issue of this particular guide.

Sorry I didn’t mean that particular guide. Another document I read from around the time of  BS 7671 : 2008 : A1 has a different recommendation. It says that if the supply system is PME, you cannot connect the neutral to the metal parts of any caravan or boat, according to Regulation 9(4) of the Electricity Safety, Quality and Continuity Regulations 2002. You can use the PME supply for permanent buildings in the marina, but not for small vessels, recreational craft or houseboats. They need a separate earth system. You can use a TT system that has its own connection with Earth, not the same as the PME earthing system, to satisfy this recommendation.

AMK said:

installing a TN-S system may be feasible.

This is very interesting ... in some IEC standards (but not IEC 60364 series), the standard implies that TN-C-S can transition to TN-S.

Of course, this is never the case, because the supply arrangement applies to the whole system.

AMK said:

installing a TN-S system may be feasible.

This is very interesting ... in some IEC standards (but not IEC 60364 series), the standard implies that TN-C-S can transition to TN-S.

Of course, this is never the case, because the supply arrangement applies to the whole system.

I was hoping that you might just gee up the beards in which ever department of the IET was responsible for this guide.
I'm a jobbing electrical contractor, I'm trying to explain to my customers that their present installation does not comply to the regs; never has and is downright dangerous or that their new installation should comply to BS 7671 and GN7.
I was hoping this 'new' guide would assist me in that task to the more tech. savvy customers.
When you start talking about transitioning TN-C-S to TNS, you're losing my attention not to mention any customers, tech. savvy or not.
This guide just does not help and I can't believe the IET would print such a thing and then have the nerve to charge us for it.
If this is the case what other misleading information have the IET printed and released over the years?
There's an Elex in Bolton soon are the IET attending? Maybe I could air my grievances there and get a response?

Hi there grahamro as Michael says above, general enquiries relating to IET codes and Guidance publications and activities, should be addressed to ietstandardsenquiries@theiet.org. Please email them with your concerns. 

The Tech Regs team have checked their mailbox and have not received any email from yourself unless you've sent it via a different name or email address? 

I rang the helpline.
The person on the phone said he would pass on my comments to the relevant department.
We spoke at length regarding electrical systems in marinas and boatyards.
At no point did he tell me to re-direct my enquiry to another department.

Hi grahamro I've just sent you a PM asking for further info