Taking cables from a house to a garage

[spinlondon]

Im suggestion that a reg relevant to street lights is not relevant to bedroom lights.You didn't state that though did you.

You stated that Regulations that are relevant to street lighting and other furniture are totally irrelevant to this discussion.

As we haven't been discussing bedroom lights, why have you made such an irrelevant comment?

Im also suggesting that anyone contemplating(never mind doing) connecting an earth electrode direct to the MET of a domestic TNCS system in the UK is unable to comply with reg16 of EAWR.

actually Im not suggesting it, that, IMO is a fact.

and Im am getting fed up trying to explain the simple basics of earthing to incompetent people that its scary just thinking about the state some peoples houses must be getting left in.

So, rather than produce evidence that supports your claims, you produce a Regulation that applies to employees, carrying out electrical work. In other words totally irrelevant to this discussion.

 

[steptoe]

So, rather than produce evidence that supports your claims, you produce a Regulation that applies to employees, carrying out electrical work. In other words totally irrelevant to this discussion.

NO,

I done something that you have been unable to do.

I have quoted the law to you.

and putting a rod to the MET of TNCS would NOT be the work of someone able to comply with that law.

 

[steptoe]

You didn't state that though did you.

You stated that Regulations that are relevant to street lighting and other furniture are totally irrelevant to this discussion.

As we haven't been discussing bedroom lights, why have you made such an irrelevant comment?

we are discussing domestic properties,

maybe you have a street light in your living room, I didnt know, sorry.

 

[PBC_1966]

I'm guessing you are referring to 542.1.1The main earthing terminal shall be connected with earth by one of the methods described in regulations 542.1.2 to 542.1.4, .........

I do understand how you are reading it

But I take that to mean it must be connected by one of them (at least) - in other words all installations must be connected to earth.

Not that it can only be connected to one of them.

And that is how I interpret it too. Must be connected by at least one of the methods, not one, and only one of the methods.

If you want to believe you are still performing installations to 7671 by putting in an earth rod then that's up to you but don't come crying to us when you get your library time in prison after someone is killed and you have found to not have complied with 7671

As somebody else has at the bottom of his posts - BS7671 is not law. And I'm still waiting to hear exactly how the provision of this extra rod is supposed to kill somebody, notwithstanding currents from other consumers' installations flowing through the cable to the earth electrode, since this is no different from the current which could just as easily flow through bonded pipework.

Incidentally, what will you call your new earthing system as PME is rodded at the PEN not the PE so its not TNCS anymore?

If the installation's earthing system is still connected to the supplier's neutral, then yes, it is still TN-C-S. Adding a purpose-made earth rod isn't going to change that, any more than bonding to that buried metallic pipework is going to change it. If the installation's earthing system is connected to the supply neutral, then it's TN. It can become TT only if the earth is the sole fault path by way of the earth electrode.

Ditto for TN-S. Adding an earth electrode isn't going to change it from TN-S to anything else, so long as that metallic fault path back to the source is still connected.

 

[PBC_1966]

eawr reg16

EAWR? Please explain how that is applicable to me adding an earth rod to my own domestic installation.

And even if we're talking about employed/self-employed work, it does not answer the question we've been asking of you in slightly different forms for the last umpteen pages.

O.K., we get that in your opinion somebody who adds an earth rod to a TN-C-S system is not competent. You've said it enough times, but not once have you actually said why you believe that to be so. Just why do you think it presents a hazard, electrically speaking?

NO its not, tell me a reg that permits TN in a normal domestic installation?you must have S on your install.

TN-S is a TN system. As you don't seem to want (or be able) to answer the questions about this I posed earlier, let's break it down:

The first T means that the supply is earthed at source. The N means that the installation is earthed via a direct metallic path back to the neutral point of that source. The letters which follow merely indicate whether that metallic path is separate from the normal current-carrying path, combined with it, or a combination of two.

Thus TN-S and TN-C-S are both TN arrangements by definition.

Im also suggesting that anyone contemplating(never mind doing) connecting an earth electrode direct to the MET of a domestic TNCS system in the UK is unable to comply with reg16 of EAWR.actually Im not suggesting it, that, IMO is a fact.

Yes, you keep on suggesting it and stating that it is your opinion. But you have not yet explained why you think so.

Im am getting fed up trying to explain the simple basics of earthing to incompetent people

But you have not done any explaining. All you are doing is quoting regulations about being competent and offering no technical explanation of just what you think it so bad about the extra earth electrode.

I'm sorry, you keep on alluding that we're incompetent and don't understand basic principles, but your responses in this thread (coupled with a few of your posts in other threads on this and related matters of earthing) are leaving me with the distinct impression that you are the one who doesn't really have a grasp of some fundamental electrical theory.

 

[SPECIAL LOCATION]

So let me get this right....... :| ?:|

did we decide if it was ok to use a bit of wood????? :Blushing

Or not?

When supplying power from a house to a separate garage, instead of burying the cables, would it be fine to attach, for example, a wooden length aerially between the buildings and run the cables in conduit along it?

wood?

not wood?

Doh!!!!!!!! :_| :_| :_| :_| :_|

 

[ianmacd]

OK this is the bottom line. The regs say one. Not one or more but one. Maybe that part could be worded better but I would not count 2 as ONE, would you? Putting more than one system into an MET would be in contrary to it only having one which means you are no longer complying with BS7671. We all know (or should know) that BS7671 is not law BUT it is a way of complying with the law. If someone is injured/killed in a domestic premesis for what ever reason that you have installed an earth rod into the MET of a TNCS system then you will not be able to use BS7671 as a defence and then you will be left alone to proove beyond shaddow of doubt that it is as safe.

Would you connect a TNCS system to a TNS system and if not, why not? Why would that be any different to connecting it to, what is in effect a TT system?

Why would you want to put an earth rod on a TNCS system anyway? If its for saftey as you believe the DNO have not put a rod near the property (and not really adhearing to the ethos of PME) then why not just remove the DNO supplied earth and make the system TT with all the provisions associated with it?

 

[ianmacd]

So let me get this right....... :| ?:| did we decide if it was ok to use a bit of wood????? :Blushing

Or not?

wood?

not wood?

Doh!!!!!!!! :_| :_| :_| :_| :_|

I thought we had but the suggestion was not to use wood as it may decay and will no longer provide suitable mechanical protection.

 

[ADS]

So let me get this right....... :| ?:| did we decide if it was ok to use a bit of wood????? :Blushing

Or not?

wood?

not wood?

Doh!!!!!!!! :_| :_| :_| :_| :_|

ROTFWL ROTFWL ROTFWL

 

[spinlondon]

Here is a link to an article in the IET's wiring matters regarding the provision of an earth rod at the installation where the supply is PME:

http://www.theiet.org/publishing/wiring-regulations/mag/pre-2004/pre14-PME-supplies-ESQC-Regs.cfm?type=pdf

 

[ianmacd]

Here is a link to an article in the IET's wiring matters regarding the provision of an earth rod at the installation where the supply is PME:http://www.theiet.org/publishing/wiring-regulations/mag/pre-2004/pre14-PME-supplies-ESQC-Regs.cfm?type=pdf

That was written in 2002 so there must be a reason it hasnt made it into 7671 in the last 8 years.

I do not care how many links/other bits people post, UNTIL its in 7671 then fitting one contravines 542.1 and you can not sign any EIC/MWC etc as having followed 7671 without deviations.

 

[spinlondon]

Amazing.

ADS posted that he had spoken both to a DNO, and the IET.

You then immediatly posted: "Got that in writing?"

I have now supplied you with written evidence from the IET's Principle engineer.

And your response is that it is 8 years old, and that it should be in the current Regulations.

Why did you ask if it was in writing?

 

[ianmacd]

Its not in an official document or ammendment to the regulations we should be following. There is nothing amazing about it.

Finding a badly written and unspellchecked document that the picture doesnt even nessessarly represent the text decribing it would hold very little (if any) weight in a court of law.

 

[spinlondon]

The article is not required to hold any weight in a court of law.

I posted it in response to your question.

I don't actually see why it would be required for a court of law.

The installation of a rod, would just be a precautionary measure for if there was ever a fault in the supply neutral.

If necessary, the publication refered to in the article, or the guidance from the Dti could easily be obtained.

 

[ianmacd]

The article is not required to hold any weight in a court of law.I posted it in response to your question.

I don't actually see why it would be required for a court of law.

The installation of a rod, would just be a precautionary measure for if there was ever a fault in the supply neutral.

If necessary, the publication refered to in the article, or the guidance from the Dti could easily be obtained.

BS7671 is followed to make sure you comply with certain laws. If you deviate then you will not have its protection in a court of law. Even I am getting bored with saying that now.

Why do you think this was never included in BS7671?

Unless you have an amendment or addition to BS7671 you are not compliant if you hook a rod up to a MET supplied by a TN system.

If you want to get an official statement (and no that iwasn't an official statement but someones opinion) on headed paper that the IET are happy to be presented in a court of law then that may hold some weight but doubtful it will be much.

 

[spinlondon]

BS7671 is followed to make sure you comply with certain laws. If you deviate then you will not have its protection in a court of law. Even I am getting bored with saying that now.Why do you think this was never included in BS7671?

Unless you have an amendment or addition to BS7671 you are not compliant if you hook a rod up to a MET supplied by a TN system.

If you want to get an official statement (and no that iwasn't an official statement but someones opinion) on headed paper that the IET are happy to be presented in a court of law then that may hold some weight but doubtful it will be much.

Bs7671 is a minimum standard, which offers an acceptable level of safety for what is considered a reasonable cost. Installing aditional safety measures that are not required by the standard, is not a deviation, and BS7671 would still offer you the same level of protection in a court of law.

It was never included in BS7671, because that standard does not cover network distribution.

So you will disregard the opinoin of the principle engineer of the IET, that the national council has determined that the provision of a rod is an acceptable method to ensure the safety of an installation in the event of a supply neutral fault.

 

[ianmacd]

You are avoiding the issue of why it's not included despite being 8 year old advice.

So you have stated it's distribution so as I said before, it's up to the DNO to put a rod in on their distribution side of the cutout. You believe it will never be in 7671 for this reason then you should surly realize it's not for us to do this work.

Also it's not extra saftey when 7671 precludes it as I have proved above with noteing 7671 says ONE system not one or more systems.

Until 7671 is updated (If it ever will be) to include mixing TT and TN installs this is a pontless discussion and now completly off topic for 200 odd posts.

Since the OP has his answers maybe it's time to close this thread.

 

[spinlondon]

You are avoiding the issue of why it's not included despite being 8 year old advice.No I am not, I explained why it is not in BS7671.

So you have stated it's distribution so as I said before, it's up to the DNO to put a rod in on their distribution side of the cutout. You believe it will never be in 7671 for this reason then you should surly realize it's not for us to do this work.

Are we not allowed to do work that is outside the scope of BS7671. I didn't realise that, when did that law come in?

Also it's not extra saftey when 7671 precludes it as I have proved above with noteing 7671 says ONE system not one or more systems.

BS7671 does not preclude it. If it did, then we would not be allowed to TT our outbuildings when the supply is TN-C-S.

There is also the fact that having a rod at the installation is not changing the earthing system, so you would still be using one system.

Until 7671 is updated (If it ever will be) to include mixing TT and TN installs this is a pontless discussion and now completly off topic for 200 odd posts.

Bs7671 doesn't need to be updated to allow mixing of TN and TT installs. I've already pointed out the Regulation that allows it.

The reason this thread is so long, is because no one who says it is unsafe to have a rod at a TN-C-S installation, or that it is unsafe to export a PME earth, has actually come up with any evidence to support their claims.

Since the OP has his answers maybe it's time to close this thread.

Perhaps you are right, it doesn't look like anyone is going to explain their view point.

 

[PBC_1966]

OK this is the bottom line. The regs say one. Not one or more but one. Maybe that part could be worded better but I would not count 2 as ONE, would you?

Well if we really want to argue over the semantics of the language rather than the electrical principles, you could say that "one" is open to same inclusive vs. exclusive interpreation as "or."

"You must do A or B" can be taken to mean that doing both is acceptable unless it is qualified somehow. Similarly, "you must do one of A, B, or C" does not automatically make those three things exclusive. You can do two of them, but have still done one of them. You just happen to have done another one as well.

If someone is injured/killed in a domestic premesis for what ever reason that you have installed an earth rod into the MET of a TNCS system

How is that going to happen?

Would you connect a TNCS system to a TNS system and if not, why not?

Normally because you have only one source of supply so you couldn't be interconnecting them. Although it does get rather interesting if a building happens to have two different types of services into it.

Why would that be any different to connecting it to, what is in effect a TT system?

It is not TT if it is earthed to the supplier's terminal. It's just TN-S or TN-C-S which has an extra earth electrode.

Why would you want to put an earth rod on a TNCS system anyway? If its for saftey as you believe the DNO have not put a rod near the property (and not really adhearing to the ethos of PME) then why not just remove the DNO supplied earth and make the system TT with all the provisions associated with it?

Because TT is not the ideal system, as recognized by codes elsewhere in the world which don't permit it at all. Why change to an inferior system when you already have TN-C-S and can improve upon it by just adding an extra electrode as a safeguard?

Tell you what, how about we don't call it an earth rod, and just bond a 5 ft. length of water pipe which happens to be driven into the ground but not used for supplying water anymore?

 

[ianmacd]

Well if we really want to argue over the semantics of the language rather than the electrical principles,I thought I was VERY clear on that earlier. Maybe you should re-read post #195, #187, probably more.

you could say that "one" is open to same inclusive vs. exclusive interpreation as "or."

How so? Or is a logical choice. Its a decision point. One is a fact. Its a number. You wouldn't say, That's 1 Mile and then accept its 2, 3,5 or another number.

"You must do A or B" can be taken to mean that doing both is acceptable unless it is qualified somehow. Similarly, "you must do one of A, B, or C" does not automatically make those three things exclusive. You can do two of them, but have still done one of them. You just happen to have done another one as well.

In English it does. As I mentioned before, or is exclusive in our spoken/written language otherwise it would be You must to A or B or C or A and B or A and C or B and C or A and B and C. English is not as flexible as logical or mathematical terms.

How is that going to happen?

You signed an EIC saying installation was to BS7671 and you fitted an earth rod. If someone is injured/killed by whatever means they will be looking at that and you will become a scapegoat. I did mention that a few times before too. It will not matter that your work did not kill them, you will not have the defence of BS7671.

Normally because you have only one source of supply so you couldn't be interconnecting them. Although it does get rather interesting if a building happens to have two different types of services into it.

That's a bit evasive isn't it?

It is not TT if it is earthed to the supplier's terminal. It's just TN-S or TN-C-S which has an extra earth electrode.

So what is it if you loose your neutral? Is it TT then or just T?

Because TT is not the ideal system, as recognized by codes elsewhere in the world which don't permit it at all. Why change to an inferior system when you already have TN-C-S and can improve upon it by just adding an extra electrode as a safeguard?

In your mind inferior? Its a perfectly acceptable system unlike what you are proposing.

Tell you what, how about we don't call it an earth rod, and just bond a 5 ft. length of water pipe which happens to be driven into the ground but not used for supplying water anymore?

That's still an earth electrode as defined in 542.2.1(i) but you need to note 542.2.4 too.

In RED.