Reworded RCD Poll

[PBC_1966]

I could add my ten cents worth that whilst RCD protection is an advantage, I'm not so sure that the modern style DIN rail CU is an advantage over older models. The older designs clamp the cores far more securely, and are thus far less likely to be the cause of a fire. Since fitting RCD protection to rings will generally mean a new CU, I'm not sure if this is a positive step or not. Some householders with 'Wylex' semi-enclosed wire fuse CUs say they don't want them changed, and I'm starting to see the wisdom behind that. These things will probably still be serviceable in 50 years' time. Not so sure about the modern ones.

I agree entirely. When those old MEM and Wylex Standard boards were the mainstay of British homes there was nothing like the reports of burned up terminals that have appeared in more recent years with the newer designs. Even if householders wanted to change from the rewireable fuses, Wylex still produces the full range of cartridge fuse carriers for the Standard range, or the plug-in MCB's.

 

[JohnD]

I can't be bothered to go and look, but I think that the old terminals had two screws each.

 

[AndyPRK]

They did.

 

[PBC_1966]

Yes - On both the main incoming terminals, and on each fuseway terminal and the neutral bar.

 

[ban-all-sheds]

Is there, or is there not, still a specific RCD exemption in BS7671 for a socket installed for supplying a particular piece of equipment and which is so labeled?

You have to have a sound reason. You can't justify omitting the RCD just because it's convenient to do so.

Did you miss my request in reply to this?

Yes.

Or did you think that responding would not support your view so decide to ignore it?

No.

I'll be charitable, assume it was the former, and ask again if BS7671 says anything about needing a specific reason.

It does not.

But it is full of all sorts of choices of provisions for all sorts of things. One of the responsibilities of a designer is to choose the most appropriate method of provision where there's a choice, such as whether a ring final or a radial would be best, or whether a buried cable should have RCD or mechanical protection, and so on.

So when it comes to providing a new socket, then yes, BS 7671 does allow RCD protection to be omitted in certain circumstances. But the question the designer must ask himself is whether that is the most appropriate thing to do. (If he is not asking himself those sorts of questions then he is not doing his job properly). If there is a need for a socket to not be RCD protected e.g. if it is to be used to check a loop tester, or to supply equipment known to be leaky, then that's fair enough.

But when someone wants a new socket for his TV, for you to say "I'll label it as "For The TV" and omit RCD protection is not a sound and appropriate design, it is a cynical attempt to avoid providing RCD protection because you CBA, or because you don't want to pay for it, or because there are existing sockets without it and the idea that regulations change causes you a throbbing in the temples.

And it is not just me telling you this.

Stillp told you this.

The IET told you this in the article you linked to.

It could. But given that they clearly don't regard existing unprotected sockets as any sort of danger, it seems unlikely, otherwise If they suddenly decided that sockets without 30mA protection were no longer to be considered reasonable provision for safety, then they would have suggested coding such in existing installations with something which indicates potential danger. They didn't.

Are you unfamiliar with the well established, widely encountered principle that when things change, and what was considered OK to be newly done yesterday is no longer considered OK to be newly done today, and what was considered OK to be newly done yesterday is not required to be updated or removed and replaced today, it just has to be no longer newly done?

I'll make you an offer:

I will stop telling you that there is a difference between assessing what is already installed and installing something new shortly after you stop pretending that there isn't.

O.K., if that's the way you intended it. But I'm sure you know it has a slightly different meaning as well.

English is a language with countless examples of words having more than one meaning.

Get over it.

What the law does not state clearly and unequivocally is that not providing 30mA RCD protection on a new socket means that you have not made the required reasonable provision for safety. That is your opinion.

What the law does not state clearly and unequivocally is that providing 30mA RCD protection on a new socket means that you have made the required reasonable provision for safety. That is your opinion.

 

[PBC_1966]

It does not.

So then the result is compliant with BS7671. Whether you think it the most appropriate choice, or whether you think it should be done only if there's a specific reason (known "leaky" equipment etc.) is irrelevant to the question of whether it complies with BS7671 if BS7671 does not make that stipulation.

In the case of the router-under-the-stairs scenario, the socket is being provided with the intent of supplying that specific piece of equipment, so if you label it as such it complies with BS7671. You've just acknowleged such, yet earlier you said it wouldn't be compliant.

So when it comes to providing a new socket, then yes, BS 7671 does allow RCD protection to be omitted in certain circumstances. But the question the designer must ask himself is whether that is the most appropriate thing to do.

And perhaps the whole point of BS7671 providing this exemption is to enable designers to consider it appropriate to omit RCD protection when the socket is intended for one specific piece of equipment, the increase in risk from such omission is absolutely minimal given the intended use, and it would involve unnecessary extra expense to provide it - The cost vs. benefit issue once again.

If the intent was that the exemption should apply only in cases such as the equipment concerned having earth leakage values which would make use of an RCD impractical, then why does the regulation not say as much?

What the law does not state clearly and unequivocally is that providing 30mA RCD protection on a new socket means that you have made the required reasonable provision for safety. That is your opinion.

Yes. I thought that was your opinion too.

 

[ban-all-sheds]

Whether you think it the most appropriate choice, or whether you think it should be done only if there's a specific reason (known "leaky" equipment etc.) is irrelevant to the question of whether it complies with BS7671 if BS7671 does not make that stipulation.

No, it does not.

BS 7671 is full of all sorts of choices of provisions for all sorts of things. One of the responsibilities of a designer is to choose the most appropriate method of provision where there's a choice, such as whether a ring final or a radial would be best, or whether a buried cable should have RCD or mechanical protection, and so on.

So when it comes to providing a new socket, then yes, BS 7671 does allow RCD protection to be omitted in certain circumstances. But the question the designer must ask himself is whether that is the most appropriate thing to do. (If he is not asking himself those sorts of questions then he is not doing his job properly). If there is a need for a socket to not be RCD protected e.g. if it is to be used to check a loop tester, or to supply equipment known to be leaky, then that's fair enough.

But when someone wants a new socket for his TV, for you to say "I'll label it as "For The TV" and omit RCD protection is not a sound and appropriate design, it is a cynical attempt to avoid providing RCD protection because you CBA, or because you don't want to pay for it, or because there are existing sockets without it and the idea that regulations change causes you a throbbing in the temples.

And it is not just me telling you this.

Stillp told you this.

The IET told you this in the article you linked to.

In the case of the router-under-the-stairs scenario, the socket is being provided with the intent of supplying that specific piece of equipment,

Why does the equipment need a non-RCD socket? You are the designer. You are exercising your skill and care. What reason do you have for deciding that an RCD protected socket would be inappropriate for the router?


And how, as designer, do you ensure that your work remains compliant? If compliance depends on the socket being used to supply only that specific piece of equipment, what can you do to make sure it is only used for that?

so if you label it as such it complies with BS7671. You've just acknowleged such, yet earlier you said it wouldn't be compliant.

What did I actually say?

And perhaps the whole point of BS7671 providing this exemption is to enable designers to consider it appropriate to omit RCD protection when the socket is intended for one specific piece of equipment,

Perhaps.

Given that you are speculating as to why, you must be open to alternative suggestions. Are you interested in authoritative guidance on what the point of the exemption is?

the increase in risk from such omission is absolutely minimal given the intended use, and it would involve unnecessary extra expense to provide it - The cost vs. benefit issue once again.

If you are going to rely on the intended use, then how do you satisfy yourself that the intended use is the only use that there will ever be?

What the law does not state clearly and unequivocally is that providing 30mA RCD protection on a new socket means that you have made the required reasonable provision for safety. That is your opinion.

Yes. I thought that was your opinion too.

Oh poo - another one messed up.

What the law does not state clearly and unequivocally is that not providing 30mA RCD protection on a new socket means that you have made the required reasonable provision for safety. That is your opinion.

 

[JohnW2]

Good grief, is this still going on! Has anything new been said in the last few pages?

Kind Regards, John

 

[PBC_1966]

Has anything new been said in the last few pages?

I think the details about the precise wording of the BS7671 RCD exemption is only a couple of pages old.....

Do you now fancy starting a new poll about non-notification of notifiable jobs?

 

[AndyPRK]

I have a new poll in mind. Just waiting for this one to finish

 

[JohnW2]

Do you now fancy starting a new poll about non-notification of notifiable jobs?

Feel free! Exactly what question did you have in mind? Whilst I'm sure that a lot of notifiable work goes unnotified (although obviously a lot less now, in England, since so little remains notifiable), quite possibly 'comfortably', by some of those who write here, but it would not be appropriate to suggest, let alone 'advise', in public, that someone should break the law.

However, as I often say, I don't think that whether or not an OP intends to break the law by failing to notify is any of our business, and nor should it influence are decision as to whether we feel it appropriate to offer (electrical) advice. As with The RCDs, we should ensure that an OP is aware of the legal requirement to notify, and then just leave it at that.

Kind Regards, John

 

[PBC_1966]

Do you now fancy starting a new poll about non-notification of notifiable jobs?

Feel free! Exactly what question did you have in mind?

Something along the lines of the RCD poll, but transferred to non-notification of notifiable jobs, with answers reflecting varying degrees of attitude from "Go on and on about it and refuse to help any further if the OP doesn't confirm that he's going to notify" down to "Note that the job is notifiable then forget about it unless the OP specifically asks for help about the notification process."

I'm not sure what precise wording would be best for the options, or how to elicit answers about projects where notification is in one of those (large) grey areas.

Not sure what Andy has in mind.....

 

[JohnW2]

Something along the lines of the RCD poll, but transferred to non-notification of notifiable jobs, with answers reflecting varying degrees of attitude from "Go on and on about it and refuse to help any further if the OP doesn't confirm that he's going to notify" down to "Note that the job is notifiable then forget about it unless the OP specifically asks for help about the notification process."

Well, I've pre-empted my personal answer to that in what I wrote in my last post. I do not think that whether or not an OP is going to notify or not has got anything to do with us, so we need do no more than make sure that (s)he is aware of the legal requirement. Whether or not we decide to give advice regarding electrical aspects of the job should depend only on our judgement regarding the OP's competence to do the work, whether (if it is notifiable work) (s)he is going to 'obey the law' (notify) or not.

Kind Regards, John

 

[PBC_1966]

So when it comes to providing a new socket, then yes, BS 7671 does allow RCD protection to be omitted in certain circumstances.

Yes, and what are those circumstances? That the socket is provided to supply a specific piece if equipment and is so labeled.

Whether you, I, or anybody else might consider it appropriate to omit the RCD if the piece of equipment would function perfectly well with it is immaterial to the question of whether it complies with BS7671 when BS7671 doesn't include such consideration as a condition of the exemption.

We weren't talking about what you or anyone else considers to be best practice, only about whether the result complies with BS7671.

In the case of the router-under-the-stairs scenario, the socket is being provided with the intent of supplying that specific piece of equipment,

Why does the equipment need a non-RCD socket? You are the designer. You are exercising your skill and care. What reason do you have for deciding that an RCD protected socket would be inappropriate for the router?

As I said already, a cost vs. benefit assessment. It's one socket, provided with the intent of feeding a specific piece of equipment, for which the absolutely tiny increase in safety RCD provision would provide may not be worth the cost of such provision compared to just running a few feet of cable to a regular socket.

And how, as designer, do you ensure that your work remains compliant? If compliance depends on the socket being used to supply only that specific piece of equipment, what can you do to make sure it is only used for that?

You don't have to do anything. Obviously the designer/installer cannot be responsible for what somebody might do later.

so if you label it as such it complies with BS7671. You've just acknowleged such, yet earlier you said it wouldn't be compliant.

What did I actually say?

In response to Andy's comment, I said:

One recent thread which comes to mind (IIRC) is that someone wanted to fit a socket under their stairs to power a router.

And which, apparently, even under the current "holy grail" of BS7671 would still be compliant without RCD protection if he just stuck a Dymo label on it saying "For computer router only - Not RCD protected" or something similar.

To which your reply was:

Wrong.

Again.

But then after you said that you need some specific reason and I asked you if BS7671 actually contains any such requirement in the exemption clause your reply was:

and ask again if BS7671 says anything about needing a specific reason.

It does not.

Again, remember this issue arose not on the basis of whether anybody might feel that it's a best practice, a good idea, or anything like that, only whether providing a socket for a specific piece of equipment and so labeling it would be compliant with BS7671.

If you are going to rely on the intended use, then how do you satisfy yourself that the intended use is the only use that there will ever be?

Where does the exemption clause say that you have to? All it says it that the socket is intended to supply a particular piece of equipment. It doesn't say that you have to be satisfied that it will never be used for anything else, which for a regular BS1363 socket would obviously be pretty much impossible to guarantee.

Back when BS7671 required RCD protection only for sockets which might "reasonably be expected" to be used to power portable equipment outdoors, were you claiming that sockets even on the second floor of a building would still need RCD protection to be compliant unless you could be satisfied that they would never be so used? (Allowing for the fact that somebody could, quite easily, drop an extension lead out of an upper window.)

 

[PBC_1966]

I do not think that whether or not an OP is going to notify or not has got anything to do with us, so we need do no more than make sure that (s)he is aware of the legal requirement. Whether or not we decide to give advice regarding electrical aspects of the job should depend only on our judgement regarding the OP's competence to do the work, whether (if it is notifiable work) (s)he is going to 'obey the law' (notify) or not.

I'm sure you won't be surprised that I agree with everything you said there. We all know that somebody could do all sorts of jobs which are not notifiable and make a dangerous mess of it, so the idea that it's "all about safety" is nonsense.

Being convinced that the person is able to do a safe job is the main issue - whether the work is notifiable or not - and if he doesn't feel like throwing away £100, £200 or more and getting tied up in local authority red-tape (especially for almost nil benefit), that's fine with me.