High integrity earthing

[Softus]

A serious safety issue perhaps, but I don't see see how this argument can ever be resolved, because, IMHO, the 16th Edition contains contradictory requirements, viz:

...shall have a high integrity protective connection complying with one or more of the following:
.
.
.
(iii) two individual protective conductors, each complying with the requirements of Section 543.

...the circuit shall be provided with a high integrity protective conductor connection complying with the requirements of Regulations 607-02 and 607-04. The following arrangements of the final circuit are acceptable:

(i) a ring final circuit with a ring protective conductor. Spurs...

If you choose to abide by the former paragraph, then a high integrity "connection" (i.e. termination method) is possible only with the use of a separate, additional, CPC.

If you choose to abide by the latter paragraph, then the requirements are met by the ordinary CPC in an ordinary RFC, as long as the terminations are made in a high integrity manner, i.e. never with two cut ends of the CPC under one screw terminal.

So which section of the 16th conveys the intended meaning of The IEE?

Even if there's a forum member who considers that sitting on a committee for a previous edition qualifies him to define the overriding interpretation, that isn't going to satisfy everyone here.

 

[NotHimAgain]

Yes - well I pointed this out earlier. My first post on the subjected recognised the problems with the text.

To understand how this may have come about you need to know how these regulations were form and how they are formed now.

This subject first surfaced in an IEC committee in the seventies - this resulted in IEC 364-07-707. It eventually made its way through CENELEC and the end result was a group of regulations inserted in to chapter 54 of the 15th Edition (June 1987 amendments).

I worked on it in th early 90's during the transition from the 15th Edition to the 16th (the requirement to separate cpc connections in DBs was my idea ).

Now during the years of the 15th, and to a lesser extent, the 16th we tended to take the technical content from CENELEC documents and produce a UK view. You will be aware that ring mains are mainly a UK system and the PVCTWE cable is effectively banned by must of our EU partners.

The 17th has attempted to achieve a greater degree of harmonization with the CENELEC documents and, as such, often uses the original text without modification. There are numerous examples of this throughout the book.

As to whether this can be resolved - well never with BAS that is for sure - his sole purpose is to prove that he is right and he is not interested in the technical issues.

For everybody else it can only be properly resolved by amending the text of this part of BS 7671. However, through all of this the basic principles have not changed and the effective solutions remain the same.

 

[ban-all-sheds]

As ever BAS you completely miss the point

As ever NHA you completely miss the point.

607-02-04 says "Two individual protective conductors". It really does - you can read it for yourself.

I don't care about your way of defining two individual protective conductors. I tried to give you a clue earlier when I pointed out that we are concerned with high integrity protective conductor CONNECTIONS.

OK, fine - if you don't care for my definition, then please come up with one of your own. Please define "individual protective conductor", not "individual protective connection", because 607-02-04 says "Two individual protective conductors", not "Two individual protective connections".

Then show how with a circuit made with two of your definition of "individual protective conductors", (not two "individual protective connections", for that is not what 607-02-04 requires) one of the two individual protective conductors could be removed thus leaving the circuit with one remaining individual protective conductor.

As ever BAS you are so bent on proving you are right that you fail to see the true problem and its solutions. You are so convinced that you somehow know more about this subject than all of the engineers that have considered it and, than all of the posters on this site.

As ever, NHA, you are so bent on proving me wrong that you fail to see the true words in the regulations. You've always assumed they mean something that they do not, and you are so convinced that you could not somehow have misinterpreted them that you will not look at them objectively.

But don't worry - there have been other posters on this site with the same attitude, you're not unique.

 

[tim west]

If you remove one of the live wires from the breaker in the CU to the first socket in relation to which wire is removed then you end up with the sockets all still being live, so how can that be if as you say i've already removed the ONLY live in the circuit??

FGS - don't be obtuse.

The conductor is of finite length, therefore it has two ends, and both are there at the CU. If you disconnect one end from the breaker the other end is still connected, therefore the conductor is still live.

but i've removed the ONLY live according to you so how does the circuit still work its baffling me??
So perhaps you should now acknowledge that i was right all the time and there are indeed TWO

 

[ban-all-sheds]

As to whether this can be resolved - well never with BAS that is for sure

Of course it can be resolved.

The regulations could be written to say that with a ring final complying with ... which has a cpc complying with ... a high-integrity cpc can be provided by {suitably unambiguous description of separate terminations}.

But until they choose to do that we are left with the fact that they have chosen to call for "two individual protective conductors".

his sole purpose is to prove that he is right and he is not interested in the technical issues.

And your sole purpose is to prove that I am wrong and you are not interested in what the text of the regulations says.

For everybody else it can only be properly resolved by amending the text of this part of BS 7671.

But until they do we are left with the current version, not what an earlier version said. It does appear though that they have chosen not to amend the text in the 17th - in fact they have added text which reinforces the requirement for two individual protective conductors and not just separate terminations.

 

[NotHimAgain]

As ever, NHA, you are so bent on proving me wrong that you fail to see the true words in the regulations. You've always assumed they mean something that they do not, and you are so convinced that you could not somehow have misinterpreted them that you will not look at them objectively.

BAS re-read my original post - where did I start off by trying to PROVE you wrong - I merely offered the comment that there could be some confusion.

Whatever makes you think that I spend my days trying to PROVE you wrong. Do you really think you are that important.

 

[ban-all-sheds]

but i've removed the ONLY live according to you so how does the circuit still work its baffling me??

I'm sorry you are baffled by the fact that ONE of these

has TWO ends

So perhaps you should now acknowledge that i was right all the time and there are indeed TWO

Sorry - when I look at this:

I see only ONE live conductor. Perhaps you would like to add to the drawing some kind of labelling which indicates where the SECOND live conductor is....

 

[Softus]

Yes - well I pointed this out earlier. My first post on the subjected recognised the problems with the text.

You may have acknowledged the conflict, but you've done nothing towards resolving it.

To understand how this may have come about you need to know how these regulations were form and how they are formed now.

I don't need to know anything about that. The bottom line is that it's self-conflicting. Since BS7671 isn't statutory, I can choose a reasonable interpretation and demonstrate my attempt to make an installation safe.

I worked on it in th early 90's during the transition from the 15th Edition to the 16th (the requirement to separate cpc connections in DBs was my idea ).

I'm sorry, I can't hear what you're saying over the noise of your own trumpet being blown.

As to whether this can be resolved - well never with BAS that is for sure - his sole purpose is to prove that he is right and he is not interested in the technical issues.

You don't know what his motivation is and goals are, so your attempt to discredit someone who's putting forward a rational argument in a rational way simply makes you look shabby. If you were truly a member a former committee, then you are a traitor to its noblesse oblige. And if that mindset is representative of the IEE committee that published the 16th Edition, then I'm not surprised at the resultant ambiguity.

For everybody else it can only be properly resolved by amending the text of this part of BS 7671. However, through all of this the basic principles have not changed and the effective solutions remain the same.

In your opinion. And it is only your opinion.

 

[Softus]

I see only ONE live conductor. Perhaps you would like to add to the drawing some kind of labelling which indicates where the SECOND live conductor is....

Don't be such a steaming great pratt - your drawing isn't representative of any live conductor in any RFC, because the live conductor is stripped and terminated at at least one accessory, even if it isn't cut.

 

[NotHimAgain]

I'm sorry, I can't hear what you're saying over the noise of your own trumpet being blown.

Well at least I have one to blow BAS

 

[NotHimAgain]

To understand how this may have come about you need to know how these regulations were form and how they are formed now.

This comment was not directed to you - whatever made you think that it was - I reiterate: don't spend my days trying to PROVE you wrong. I have more important to do - well maybe not right now but - hey we all need a laugh now and then.

 

[tim west]

That was Softus not Bas you quoted

 

[NotHimAgain]

You don't know what his motivation is and goals are, so your attempt to discredit someone who's putting forward a rational argument in a rational way simply makes you look shabby. If you were truly a member a former committee, then you are a traitor to its noblesse oblige. And if that mindset is representative of the IEE committee that published the 16th Edition, then I'm not surprised at the resultant ambiguity.

That will be the committee full of fools then will it.

BAS you protest too much .

 

[Softus]

To understand how this may have come about you need to know how these regulations were form and how they are formed now.

This comment was not directed to you - whatever made you think that it was

I suppose it was the fact that you wrote it in the post (this one) that was directed at me. I'm starting to think that you don't know what the buggery bollocks is going on here.

I reiterate: don't spend my days trying to PROVE you wrong. I have more important to do - well maybe not right now but - hey we all need a laugh now and then.

What?

 

[NotHimAgain]

That was Softus not Bas you quoted

If that is directed at me - I quoted myself not softus.